Quantifi Photonics IQTX 1100 Series User manual

Coherent Modulation Transmitter | IQTX
Quantifi Photonics Ltd. Version 1.042
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without the prior written permission of Quantifi Photonics Ltd. (Quantifi Photonics).
Information provided by Quantifi Photonics is believed to be accurate and reliable.
However, no responsibility is assumed by Quantifi Photonics for its use nor for any infringements of
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The information contained in this publication is subject to change without notice.
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Quantifi Photonics’ trademarks have been identified as such. However, the presence or absence of such
identification does not affect the legal status of any trademark.
LabVIEW™, MATLAB® and Python® are trademarks of National Instruments, The MathWorks Inc., and the
Python Software Foundation, respectively. Neither Quantifi Photonics nor any software programs or
other goods or services offered by Quantifi Photonics are affiliated with, endorsed by, or sponsored by
National Instruments, The MathWorks Inc., and the Python Software Foundation.
Units of Measurement
Units of measurement in this publication conform to SI standards and practices.
EU Authorized Representative
Certification Company
Veluwezoom 42
1327 AH ALMERE
The Netherlands
[phone]
[email protected]
Version: 1.04

Coherent Modulation Transmitter | IQTX
Quantifi Photonics Ltd. Version 1.043
Contents
1Conventions........................................................................................................................... 6
2Safety information...............................................................................................................7
Optical laser radiation precautions.......................................................................................................................... 7
FDA Certification ............................................................................................................................................................... 7
Electrostatic discharge precautions........................................................................................................................ 7
Electromagnetic compatibility....................................................................................................................................8
3Introducing the IQTX .......................................................................................................... 9
IQTX 1100 Series overview & features......................................................................................................................9
IQTX 1200 Series overview & features .................................................................................................................. 10
4Working with electrical connectors.............................................................................. 11
Connector care ..................................................................................................................................................................11
Making a connection.......................................................................................................................................................11
Separating a connection ..............................................................................................................................................12
Using a torque wrench...................................................................................................................................................12
Torque settings..................................................................................................................................................................13
5Working with optical fibers.............................................................................................14
Cleaning and connecting optical fibers.................................................................................................................14
6Setting up IQTX and powering ON ...............................................................................15
Setting up IQTX and powering ON ...........................................................................................................................15
Setting up IQTX for single polarization (IQTX 1100 Series models only) ................................................. 16
Setting up IQTX for dual polarization......................................................................................................................17
6.3.1 IQTX 1100 Series (Emulated Dual Polarization)...................................................................................17
6.3.2 IQTX 1200 Series (Full Dual Polarization) ..............................................................................................17
7Installing software .............................................................................................................18
Installing Cohesion Operator software package on client computer(s) ................................................18
Checking instrument firmware versions and other product information ........................................... 20
Upgrading an instrument with the latest firmware .........................................................................................21
Restoring factory settings on an instrument .................................................................................................... 22
8CohesionUI –Overview ...................................................................................................23
Accessing CohesionUI.................................................................................................................................................. 23
Home page........................................................................................................................................................................ 24
Setting values................................................................................................................................................................... 24
SET values and ACTUAL values............................................................................................................................... 25
Managing CohesionUI settings ............................................................................................................................... 25
Managing network settings .......................................................................................................................................27
8.6.1 Setting the USB IP address........................................................................................................................27
8.6.2 Setting the Ethernet IP address ..............................................................................................................27

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Info panel............................................................................................................................................................................ 29
9Operating IQTX with CohesionUI.................................................................................30
Setting the modulation channels mode............................................................................................................... 30
Setting the modulation channels bias values.....................................................................................................31
Output power value.........................................................................................................................................................31
Initiating a DC-bias scan ..............................................................................................................................................31
Setting the laser source parameters.................................................................................................................... 32
Tuning the laser source............................................................................................................................................... 32
9.6.1 Grid setting and min & max frequency values ................................................................................ 32
9.6.2 Frequency tuning........................................................................................................................................... 33
9.6.3 Frequency fine tuning.................................................................................................................................. 34
Toggling the laser on / off .......................................................................................................................................... 35
Setting the dither size .................................................................................................................................................. 35
Setting the dither interval .......................................................................................................................................... 36
Reviewing modulator bias values vs time error history plots.....................................................................37
Reviewing modulator biases power vs biases voltage plots ..................................................................... 38
10 Operating IQTX from the LCD interface ...................................................................40
Powering on / off the IQTX instrument................................................................................................................. 40
LCD control touch-screen Graphical User Interface (GUI) ......................................................................... 40
10.2.1 Main display..................................................................................................................................................... 40
10.2.2 Setting laser channel parameter values............................................................................................ 40
10.2.3 Toggling the laser channel on / off..........................................................................................................41
10.2.4 Setting modulation channel parameters .............................................................................................41
10.2.5 Settings menu ...................................................................................................................................................41
10.2.6 Navigation within the settings menu.................................................................................................... 42
10.2.7 Device information........................................................................................................................................ 42
10.2.8 Ethernet connectivity configuration ..................................................................................................... 42
10.2.9 USB connectivity configuration .............................................................................................................. 42
10.2.10 ABC setup settings ....................................................................................................................................... 43
10.2.11 Unit settings ..................................................................................................................................................... 43
10.2.12 Step size settings........................................................................................................................................... 43
10.2.13 LCD calibration reset................................................................................................................................... 43
11 Programming guide .........................................................................................................45
Programming conventions ........................................................................................................................................ 45
11.1.1 Index addressing of modules (slot, source) and units (channel).............................................. 45
Status and event registers ........................................................................................................................................ 46
11.2.1 Standard Event Status Register............................................................................................................. 46
11.2.2 Standard Event Status Enable Register (Mask) ............................................................................. 46
11.2.3 Status Byte Register .................................................................................................................................... 46
11.2.4 Service Request Enable Register (Mask)........................................................................................... 46

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Common system command summary..................................................................................................................47
Common system command descriptions............................................................................................................47
Specific command summary.................................................................................................................................... 50
Specific command descriptions................................................................................................................................51
11.6.1 System commands.........................................................................................................................................51
11.6.2 Slot commands.................................................................................................................................................51
11.6.3 Configuration commands.......................................................................................................................... 52
SCPI Command Console ............................................................................................................................................60
12 Example: Control of the IQTX with SCPI ...................................................................63
NI-MAX application........................................................................................................................................................ 64
NI-VISA application........................................................................................................................................................ 65
Python® 2.7 code example..........................................................................................................................................66
MATLAB® code example ..............................................................................................................................................67
13 Example: QPSK configuration procedures ..............................................................68
Set the laser frequency and power .......................................................................................................................68
Setting RF delay for IQ Skew (optional, certain models only).................................................................... 68
13.2.1 I & Q RF delay adjustment......................................................................................................................... 68
13.2.2 IQ skew ............................................................................................................................................................... 68
Modulator adjustments...............................................................................................................................................69
13.3.1 Modulator bias-I and bias-Q .................................................................................................................... 69
13.3.2 I & Q optical phase offset ...........................................................................................................................70
14 Measurement definitions ................................................................................................ 71
IQ RF imbalance................................................................................................................................................................71
Error vector.........................................................................................................................................................................71
15 Maintenance....................................................................................................................... 72
Annual calibration schedule.......................................................................................................................................72
16 Technical support.............................................................................................................. 73
Contacting the Technical Support Group............................................................................................................73
Transportation..................................................................................................................................................................73
17 Warranty .............................................................................................................................. 74
General information.......................................................................................................................................................74
Liability .................................................................................................................................................................................74
Exclusions............................................................................................................................................................................74
Certification .......................................................................................................................................................................74
Service and repairs ........................................................................................................................................................74

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1Conventions
Before using the IQTX instrument described in this manual, take note of the following conventions:
Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
Do not proceed unless the required conditions are met and understood.
Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury. Do not proceed unless the required conditions are met and understood.
Indicates a potentially hazardous situation which, if not avoided, may result in component damage.
Do not proceed unless the required conditions are met and understood.
Refers to information about this product that you should not overlook.
Indicates some information that requires your attention or some extra information for the current
topic.

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2Safety information
Before using the IQTX instrument, ensure that the following safety information has been read and
understood.
Optical laser radiation precautions
Do not install or terminate fibers while the light source is active. Care must be taken to ensure
that the instrument has been turned OFF before inspecting the end face(s) of the instrument,
or any optical patch cords connected to this instrument. Never look directly into a live fiber;
ensure that your eyes are protected at all times.
The use of controls, adjustments, and procedures other than those specified herein may result
in exposure to hazardous situations involving optical radiation.
FDA Certification
This IQTX complies with 21 CFR 1040.10 and 1040.11 except for deviations pursuant to laser notice no.50,
dated June 24, 2007.
Electrostatic discharge precautions
The IQTX is sensitive to electrostatic discharge (ESD). Store the unused instrument in the
original protective electrostatic packaging that the IQTX was shipped in.
Ensure that a wrist strap and grounding table mat is used when unpacking or handling the IQTX
instrument. Proper grounding and ESD management practices should always be followed to ensure that
no ESD damage is caused to the IQTX instrument.

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Electromagnetic compatibility
•For electromagnetic compatibility, this instrument is a Class A product. It is intended for use
in an industrial environment. There may be potential difficulties in ensuring electromagnetic
compatibility in other environments, due to conducted as well as radiated disturbances.
•Wherever the symbol is printed on the unit, refer to the instructions provided in the
device documentation for related safety information. Ensure that the required conditions
are met and understood before using the product.

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3Introducing the IQTX
The IQTX enables quick and simple generation of phase modulated optical signals in one, simple to use,
bench-top package.
The IQTX is available in two configurations - single-polarization with dual-polarization emulator and full
dual-polarization, allowing the customer flexibility from the outset. Its high bandwidth of up to 40 GHz
(typical) ensures high quality optical signal generation, even at Baud rates exceeding 80 Gbaud, making
it the ideal 'Golden' optical signal source for coherent communications applications. It uses the highest
quality, high bandwidth, linear RF amplifiers to enable generation of any multi-level optical modulation
formats when used with an RF Arbitrary Waveform Generator (AWG).
IQTX’s emulated dual-polarization capability uses optical multiplexing technique to generate a dual-
polarization signal from a single-polarization modulated signal. It enables the use of only two channels
of RF signal source to generate a dual-polarization coherent modulation format, leading to a significant
system cost reduction. This approach is widely used in R&D environments where there is no need to
have independent data pattern on all four tributaries.
The IQTX comes with a narrow linewidth, high-power, tunable internal laser, which can conveniently be
controlled using the touchscreen LCD or remotely from a PC using the web-based software interface.
The internal laser is externally connectorized on the front panel for maximum flexibility. Users simply
connect its output to the modulator input using a short PMF patch cord supplied with the instrument.
This external connection allows you to use your own laser if preferred.
IQTX 1100 Series overview & features
Front panel
1Power On / Off
2Built-in laser output PM FC/PM
3Modulator laser input PM FC/PC
4Dual-Pol emulator input PM
5Modulated single-Pol signal output PM
6Dual-Pol emulator input PM
7Dual-Pol emulator output PM
8RF signal In-Phase input
9RF signal Quadrature input
10 LCD screen
11 Connector type information
Rear panel
12 USB connection to PC
13 Ventilation fans (DO NOT OBSTRUCT)
14 Ethernet port
15 Chassis grounding screw
16 Mains power on / off isolation switch
17 AC power ~100 - 240 V; 50/60 Hz;
70 W Max

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IQTX 1200 Series overview & features
Front panel
1Power On / Off
2Built-in laser output PM
3Modulator laser input PM
4Modulated Dual-Pol signal output
5RF signal X-Pol-I input
6RF signal X-Pol-Q input
7RF signal Y-Pol-I input
8RF signal Y-Pol-Q input
9LCD screen
10 Connector type information
Rear panel
11 USB connection to PC
12 Ventilation fans (DO NOT OBSTRUCT)
13 Ethernet port
14 Chassis grounding screw
15 Mains power on / off isolation switch
16 AC power ~100 - 240 V; 50/60 Hz; 70 W Max
•You must use the IEC cable that has been supplied by Quantifi Photonics with the unit

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4Working with electrical connectors
Quantifi Photonics products are equipped with high-quality RF signal connectors.
Connector care
Although all connectors eventually wear, with proper technique you can maximize accuracy and
repeatability of measurements, and the lifetime of coaxial connectors:
•Use high quality cables, connectors and adapters to avoid damaging the unit. Mating of low
quality SMA components to female connectors may damage or degrade the female center pin.
•Handle connectors in the high-frequency range with precision dimensions properly to avoid
inadvertent damage.
•Avoid bad connections due to malfunctioning connectors as they are the most common cause
of measurement errors.
•Where possible, avoid frequent connections/disconnections of the RF Coax array on the front
panel as it will gradually wear each time the harness is connected or disconnected.
•Do not bend or deform rigid cables, as this will cause damage
Use ESD protection at all times, especially when handling RF input / output connectors.
Making a connection
When making a connection:
•Wear a grounded wrist strap.
•Inspect, clean, and gauge connectors. All connectors must be undamaged, clean, and within
mechanical specification.
•Carefully align the center axis of both devices. Push the connectors straight together so they
can engage smoothly. The male center conductor pin must slip concentrically into the contact
finger of the female connector.
Rotate only the connector nut —NOT THE DEVICE OR CONNECTOR BODY —until finger-tight,
being careful not to cross the threads. Damage to both connectors will occur if the male center
pin is allowed to rotate in the female contact fingers.

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Separating a connection
When separating a connection:
•Support the devices to avoid any twisting, rocking, or bending force on either connector.
•Use an open-end wrench to prevent the device body from turning.
•Use another open-end wrench to loosen the connector nut.
•Complete the disconnection by hand, turning only the connector nut.
•Pull the connectors straight apart.
Using a torque wrench
Applying the correct torqueing force by using a torque wrench avoids damage due to over or under
tightening connections. It significantly improves measurement accuracy and repeatability at mm-wave
frequencies, avoids signal failure and extends connector life.
When using a torque wrench:
•Make sure the torque wrench is set to the correct torque setting (refer 4.5 Torque settings).
•Position torque wrench, and a second wrench to hold the device or cable, within 90° of each
other before applying force. Make sure to support the devices to avoid putting stress on the
connectors.
•Hold the torque wrench lightly at the end of the handle then apply force perpendicular to the
torque wrench handle. Tighten until the “break” point of the torque wrench is reached. Do not
push beyond initial break point.

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Torque settings
Wrench type
Torque settings
1.0 mm
4 in-lb (45 N-cm)
1.85 mm
8 in-lb (90 N-cm)
2.4 mm
8 in-lb (90 N-cm)
NMD 2.4 mm
8 in-lb (90 N-cm)
2.92 mm
8 in-lb (90 N-cm)
3.5 mm
8 in-lb (90 N-cm)
NMD 3.5 mm
8 in-lb (90 N-cm)
SMA
5 in-lb (56 N-cm)

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5Working with optical fibers
Quantifi Photonics products are equipped with high-quality optical connectors in compliance with EIA-
455-21A standards.
To ensure maximum power and to avoid erroneous readings always inspect fiber end faces.
Make sure they are cleaned as detailed below before inserting into any port. Quantifi Photonics
is not responsible for damage or errors caused by bad fiber cleaning or handling.
The type of optical connectors on the IQTX instrument can be found printed on the front plate of
the product. Joining mismatched connectors will damage the ferrules and fibre faces.
Do not connect FC/APC type connectors directly to the instrument, as it will damage the
connector. A convertor patch cord can be used in case FC/APC connectors are needed.
To keep connectors clean and in good condition, Quantifi Photonics strongly recommends inspection
with a fiber inspection probe before connecting them. Failure to do so will result in permanent damage
to the connectors and degradation of future measurements.
Cleaning and connecting optical fibers
To connect the fiber-optic cable to the port:
1. Inspect the fiber using a fiber inspection microscope. If the fiber is clean, proceed to connect it
to the port (step 6).
2. If the fiber is dirty, clean it as detailed below.
3. Gently wipe the fiber end with a lint-free swab dipped in isopropyl alcohol.
4. Use compressed air to dry completely.
5. Visually inspect the fiber end to ensure its cleanliness.
6. Carefully align the connector and port to prevent the fiber end from touching the outside of the
port or rubbing against other surfaces. If the connector features a key, ensure that it is correctly
mated into the corresponding notch of the port bulkhead.
7. Push the connector in so that the fiber-optic cable is firmly in place, thus ensuring adequate
contact. If your connector features a screw sleeve, tighten the connector enough to firmly
maintain the fiber in place. Do not over tighten, as this will damage the fiber and the port
bulkhead.
If your fiber-optic cable is not properly aligned and/or connected, you will notice large signal
loss and reflection .

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6Setting up IQTX and powering ON
Setting up IQTX and powering ON
The RF signal connectors are used to input an RF generated pattern for optical transmission. Depending
on the IQTX model, a single or dual polarization optical signal can be generated from the RF input
signals.
•Ensure that the IQTX is ON before applying any RF signals to the RF signal inputs.
•Ensure the input RF signal voltage remains below the specified 500 mV pk-pk.
•For advice on connector care, refer section 4 Working with electrical connectors.
•The IQTX is sensitive to ESD. Ensure you are wearing a grounded wrist strap at all times
when handling the instrument to prevent damage from electrostatic discharge.
•Do not remove the IQTX instrument from the antistatic packaging until required.
•Take care not to handle the optical connectors on the IQTX instrument, as once they are
exposed to skin contact this may leave corrosive residue and damage the connector.
•You must use the IEC cable that has been supplied by Quantifi Photonics with the unit.
STEP 1: Connect AC mains power to the instrument to provide ground connection.
STEP 2: Via USB –Connect a USB cable
STEP 2: Via Ethernet –Connect an Ethernet cable
STEP 3:
Make all required electrical and optical connections. For details refer section Setting up IQTX for
single polarization or Setting up IQTX for dual polarization.

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Setting up IQTX for single polarization (IQTX 1100 Series models only)
•Ensure that the IQTX is ON before applying any RF signals to the RF signal inputs.
•Ensure the input RF signal voltage remains below the specified 500 mV pk-pk.
•For advice on connector care, refer 4 Working with electrical connectors.
To generate a single polarization signal (QPSK) aligned to a single state of polarization:
1. Connect the data channels from the RF source to the In-phase and Quadrature RF signal inputs.
2. Connect the Internal Laser Output to the Modulator Laser Input using the short (20 cm) blue PM
patch cord supplied with the instrument. Alternatively, you can connect your own narrow-
linewidth Laser with a PM output using a PM patch cord (linewidth needs to be less than 500 kHz).
3. Use the output port of the modulator for a linearly polarized single polarization signal.
The power level going into the modulator Laser input port must not exceed the Max Input power
specified for the model.
STEP 4:
Once all connections are completed, turn ON the
isolation switch located next to the mains socket.
The switch will illuminate indicating that the AC
power supply is live and the IQTX is ready to be
powered ON.
STEP 5:
Power ON the instrument.
STEP 6:
IP address will appear on the LCD screen. If IQTX is connected via Ethernet and USB, the display will
alternate between the USB and Ethernet IP address (for details refer section 10.2.1).
After powering on, please wait at least 1 minute before attempting to communicate with IQTX. This
gives IQTX time to finish boot procedures and initialize the communication server.

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Setting up IQTX for dual polarization
IQTX models enable to generate dual polarization signals where the optical signal can be transmitted
along two orthogonal polar planes in the optical fiber. However, the IQTX 1100 Series will only duplicate
and delay modulated signals along both polarizations.
optical fiber
•Ensure that the IQTX is ON before applying any RF signals to the RF signal inputs.
•Ensure the input RF signal voltage remains below the specified 500 mV pk-pk.
•For advice on connector care, refer section 4 Working with electrical connectors
6.3.1 IQTX 1100 Series (Emulated Dual Polarization)
To generate a dual polarization signal:
Follow the instructions in section
Setting up IQTX for single polarization (IQTX 1100 Series models only) establish a single polarization
modulation signal.
1. Connect the Single Polarization SIGNAL OUT to the Dual Polarization SIGNAL IN using a PMF
patch-cord, to generate the Y-pol modulation signal.
2. The dual polarization modulated signal generated from the input RF pattern is then output from
the optical port labelled Dual Polarization SIGNAL OUT.
6.3.2 IQTX 1200 Series (Full Dual Polarization)
The IQTX 1200 Series instrument can generate optical signals from up to four independent RF channel
sources. One channel pair from the RF input signals is modulated on the X-pol, the second pair is
modulated on the Y-pol.
To generate a dual polarization signal:
1. Connect the data channels from the RF source to the RF Signal Inputs IN-PHASE electrical and RF
Signal Inputs QUADRATURE connectors.
2. Connect the internal Laser output to the Modulator Input. If using your own narrow-linewidth Laser,
the linewidth needs to be less than 500kHz.
Please make sure the Laser power connected to the modulator input does not exceed the
maximum optical power specification.
3. The dual polarization modulated signal is output from the modulator output port.

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7Installing software
Installing Cohesion Operator software package on client computer(s)
Set up any computer you use to connect with the instrument by installing the latest Cohesion Operator
software package. Cohesion Operator enables you to connect with Quantifi Photonics instruments on
your network and manage firmware upgrades.
The package is included on the USB media device that we provide with your instrument, or you can
download it from quantifiphotonics.com (go to Resources > Drivers, software and manuals > EPIQ
Series).
If another IQTX instrument is already connected to the client computer over USB, consult the
Network and Update settings on configuring the Ethernet / USB IP address for multi-instrument
control.
To install the software package on a client computer:
•(recommended) Save your work and close all programs.
•If using the USB media device, insert it on the computer.
•Double-click CohesionOperator-<version>.exe and follow the prompts.
A Windows Security Alert may prompt you to allow network access. We recommend that you
allow access to both, private and public networks, to enable any network configuration.
The installation wizard will install required drivers, applications, and desktop icons on the
computer.
To open the Cohesion Operator application:
•Double-click the Cohesion Operator desktop icon or open Cohesion Operator from the Start
menu.
From Cohesion Operator you can:
1. Select a Quantifi Photonics instrument that is available on your network.
2. Validate the IP address of the instrument and retrieve instrument information (refer 0).
3. Communicate with the instrument through the SCPI Command Console (refer 11.7).
4. Access the instrument through CohesionUI, a web-based graphical user interface (refer 8.1).
5. Upgrade instrument firmware (refer 7.3).
6. Restore the instrument to factory settings (refer 7.4).

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Checking instrument firmware versions and other product information
You can check the details of an instrument in Cohesion Operator or in CohesionUI.
In Cohesion Operator:
1. Select the instrument.
2. Click Connect.
3. Current instrument information will be displayed.
In CohesionUI:
1. Select INFO on the menu.
2. Instrument information will be displayed in the info panel.