General photonics Pos-002 User manual

POS – 002

Fiber-Optic Polarization Tracker

Operation Manual

September 27, 2013

General Photonics Corp. Ph: (909) 590-5473

5228 Edison Ave. Fax: (909) 902-5536

Chino, CA 91710 USA www.generalphotonics.com

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WARRANTY

All of General Photonics’ products have been inspected and found to comply with our

stringent quality assurance standards before shipping. If any damage occurs during

shipment, please contact the carrier and inform us or our distributors as soon as possible.

Please do not, under any circumstances, attempt user repair of any General Photonics

product. To avoid further damage, any repair of defective products must be performed by

well-trained engineers.

General Photonics warrants that this product will be free from defects in materials or

workmanship for a period of one year from the date of original shipment (listed on the

certificate of quality or packing list enclosed with the original shipment). A product

found to be defective during the warranty period will be repaired or replaced, at no

charge, at General Photonics’ option.

If a problem is found, please contact General Photonics for assistance. If necessary,

return the defective product, freight prepaid, clearly labeled with the RMA number, with

as complete a description of the problem as possible. The repaired or replacement product

will be returned, freight prepaid, as soon as possible.

The above warranty specifically excludes products that have been repaired or modified

by non-manufacturer-authorized personnel, as well as damage caused by misuse, abuse,

improper storage or handling, or acts of nature.

This warranty is in lieu of all other warranties, expressed or implied. General Photonics

will not be liable for any indirect or consequential damages or losses resulting from the

use of its products.

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SAFETY CONSIDERATIONS

The following safety precautions must be observed during operation, service and repair

of this product. Failure to comply with these precautions or with specific warnings

elsewhere in this manual violates safety standards of design, manufacture, and intended

use of the product. General Photonics Corp. assumes no liability for customers’ failure to

comply with these requirements.

•Before operation, the user should inspect the product and review

the manual carefully.

•Make sure that the product is in a secured work environment (in terms of

temperature, humidity, electrical power, hazard due to fire or shock, etc.) for

proper operation.

•Standard laser safety procedures should be followed during operation.

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Table of Contents:

Section 1. Specifications:.................................................................................................. 5

Section 2. Overview: ......................................................................................................... 6

Section 3. Feature Descriptions:...................................................................................... 8

3.1 Optical Features:...................................................................................................... 8

3.2 Electrical Features:.................................................................................................. 9

Section 4. Operation Instructions:................................................................................. 10

4.1 Unpacking .............................................................................................................. 10

4.2 Getting Started........................................................................................................ 11

4.3 Testing and Characterization:............................................................................... 12

4.4 Remote control and programming:....................................................................... 13

4.4.1 RS-232 Connection.................................................................................. 13

4.4.2 Remote operation and commands......................................................... 14

4.4.3 RS-232 troubleshooting.......................................................................... 22

4.4.4 LabView control program...................................................................... 22

Section 5. Application Examples ................................................................................... 26

5.1 PMD compensation................................................................................................ 26

5.2 Polarization Demultiplexing.................................................................................. 27

5.3 Coherence detection............................................................................................... 29

5.4 Polarization tracking for sensor system................................................................ 29

Section 6. Technical Support ......................................................................................... 30

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Section 1. Specifications:

Physical Features:

Package Dimensions 7.25” (L) × 3.86” (W) × 0.75” (H)

Fiber Input/Output Connectors1FC/PC or FC/APC

Weight 2lbs

System Specifications:

Operating wavelength21310 or 1550±50 nm standard

SOP Recovery Time < 3 ms (0.9 ms typical)

SOP accuracy3< 0.1 dB

Repeatability < 0.1 dB

SOP Rotation tracking speed (reset free) 47π/s

Insertion loss Internal feedback: 0.8 dB typ., 1.2 dB max.

External feedback: <0.1 dB

Return loss > 50 dB

Isolation in orthogonal polarization >20 dB

Optical input power −20 dBm to 20 dBm for internal feedback

version

Optical power damage threshold 300 mW

Operation temperature 0 °C to 70 °C

Storage temperature −20 °C to 70 °C

Power Supply DC +12V / 0.5A

−12V / 0.15A

External feedback voltage 0.5 to 4.6V DC (ext. feedback version only)

Communications interface4RS-232

Notes: Specifications listed above are for the standard configuration; specs may be

different for instruments with different wavelength or input power ranges.

1. Per user specification when product is ordered.

2. Other wavelengths and control algorithms may be available upon request.

3. The output power fluctuation caused by SOP fluctuation after passing through a

polarizer.

4. Requires special cable (provided).

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Section 2. Overview:

The POS-002 is a compact fiber-optic polarization tracker module designed and

manufactured by General Photonics Corporation. It integrates General Photonics’ award-

winning PolaRite™ III polarization controller, an optical polarization detection circuit,

and a microprocessor based electronic control circuit into an automatic, remote-

controllable system. The POS-002 is packaged in a small, watertight enclosure for easy

integration into user systems, as shown in Figure 1. Its fast response, low insertion loss,

and reset-free operation make it well-suited for use in coherent communications, fiber-

optic sensors, fiber-optic interferometers, and other applications that require an actively

optimized state of polarization (SOP). General Photonics’ proprietary polarization control

algorithm allows the POS-002 to compensate for sudden polarization discontinuities as

well as continuous slow polarization drift in one or more directions.

The standard POS-002 polarization tracker with SM output fiber covers the 1260-1650

nm fiber transmission window. A short wavelength custom version can also be made to

cover a wavelength range from 970 nm to 1260 nm. Versions with PM output typically

have a wavelength range of center wavelength ±50nm.

Figure 1 POS-002 polarization tracker module for fiber-optic systems

The operation of the POS-002 is based on a feedback system, as shown in Figure 2. It is

internally controlled by a microprocessor.

For versions with internal optical feedback control, the POS-002’s internal polarization

monitoring system is based on General Photonics’ PolaDetect™ polarimeter or a

simplified version. The polarization monitoring system intercepts only a small fraction

of input light, so that the total insertion loss of the system is small (<1 dB) for totally

polarized input light.

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For an arbitrary input polarization state, the polarization monitor measures the output

polarization state and then sends a feedback signal to the polarization controller. The

optimization process is repeated until the desired output SOP is achieved.

The POS-002 can also be factory configured to use external feedback control. In this

case, the feedback signal is a DC or quasi-DC voltage generated by the user. This

feedback signal can correspond to any parameter that is to be optimized by the

polarization controller, such as digital clock level, optical extinction ratio, clear eye

pattern area, receiver power level, local oscillator level, interferometer fringe contrast,

SOP, etc. In this configuration, the polarization monitor unit (composed of the

components in the dashed line box shown in Figure 2) is not installed. In this case, the

optical path of the entire module is a continuous section of optical fiber. Therefore, the

optical insertion loss from the polarization controller can be disregarded.

Figure 2 POS-002 polarization tracker block diagram.

Standard model with internal optical feedback

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Section 3. Feature Descriptions:

3.1 Optical Features:

The POS-002 polarization tracker has two optical fiber connectors: an input connector to

receive the input light beam and an output connector to couple the polarization optimized

light beam downstream. The input/output fiber connector type can be specified by the

user when the module is ordered.

All fiber connectors should be cleaned using industry standard cleaning methods before

making connections to the POS-002.

There are two output fiber options for POS-002 modules: PM output fiber and single

mode (SM) output fiber, as shown in Figure 3 (a and b). The two output options have

different features.

The internal feedback POS-002 has PM fiber output. In this configuration, a linear

polarizer is inserted in the optical path. Therefore, the output SOP is fixed, and is aligned

to the slow axis (default) or fast axis (if the user specifies it) of a PM fiber. With the

POS-002 disabled, the output power can fluctuate if the input SOP changes. Once the

tracker is enabled, the output power will be stabilized along with the SOP. The PM fiber

output version of the POS-002 is extremely useful when the fiber-optic

component/system following it has PM fiber at the input. Examples include electro-optic

modulators or PM coupler/combiners.

The external feedback POS-002 has SM fiber output. In this configuration, there is no

polarizer in the output optical path. Therefore, the output optical power is a constant.

Once the tracker is enabled, the output SOP will be actively adjusted to optimize the

parameter of interest. If the feedback signal is set up for SOP stabilization, this means

that the SOP will be confined to a tiny circle on the Poincaré sphere centered on the

target SOP. This configuration is useful when the fiber optic system following the POS-

002 has SM fiber at the input.

POS-002 POS-002

(a) (b)

Figure 3 Two output configurations of the POS-002 polarization tracker: (a) fixed SOP with

stabilization in optical power, and (b) fixed output power with stabilization in SOP

For internal feedback units, the maximum input optical power is approximately +20dBm

(100 mW). For optical power higher than 20 dBm (100 mW), please contact General

Photonics, or specify when ordering.

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3.2 Electrical Features:

The POS-002 uses a microprocessor based measurement system. The polarization

tracking function is continuously monitored and fully automatic. There are no user

serviceable parts in the system, and no calibration is required.

The POS-002 requires + 12V/0.5A and −12V/0.15A DC power supplies. Due to the

presence of internal high voltages, the following safety precautions must be exercised

during operation.

•The ground pin on the power cable must be connected to earth ground of the

power supply.

•Never touch the boards inside the package without proper insulation and

grounding.

•The POS-002 is not user serviceable and can be serviced only by factory-

authorized personnel.

The power and communication connections and pin definitions for the POS-002 are listed

below. Pin definitions and labels are also shown on the POS-002 overlay (see cover

picture or Figure 1). An RS-232 interface (using the special cable provided) can be used

for remote control operation. A 2-part cable is provided for power/communication

connections to the POS-002. The first section connects to the POS-002 module, and

includes the functions shown in the pin definition in Table 1: power, RS-232, and

external feedback signal input (for external feedback version POS-002). The second

section connects to the 3-pin connector on the first section, and has a DB9 connector on

the other side for RS-232 interface with a computer. Remote operation can be achieved

by using any program that supports the RS-232 communication protocol. A simple

LabView™ (National Instruments, www.ni.com) interface is provided for RS-232

control. RS-232 control commands are listed in Section 4.4.1, and Section 4.4.4 contains

a description of the control program.

Figure 4 POS-002 electrical/communication connector

110

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Table 1 Electrical/communication connector pinout

Pin Definition

1 Not Used

2 +12VDC

3 GND

4 −12VDC

5 COMGND

6 RXD

7 TXD

8 EXTSIG (external feedback)

9 GND

10 Not Used

Section 4. Operation Instructions:

Electrical and optical connections are required during initial setup of the POS-002. The

relevant safety precautions should be followed when making these connections.

Warnings:

•Never look into the light source fiber connector when light source is turned

on. THE OUTPUT LIGHT FROM A HIGH POWER LASER IS

HARMFUL TO HUMAN EYES. Please follow industry standard procedures

when operating a high power laser source.

•Although the POS-002 is packaged in a watertight enclosure, it still requires

external electrical connections. It is therefore advisable to avoid water

condensation or liquid spills in its vicinity at all times.

•Check optical power level of the input optical beam. Make sure the optical

power level at the input connector is below 20 dBm (100 mW).

4.1 Unpacking

Inspect POS-002 to check for any physical damage due to shipping and transportation.

Contact carrier if any damage is found. Check the packing list for any missing parts or

accessories.

Avoid excess vibration environments when using the POS-002 system. External high

frequency vibration may affect the accuracy of SOP stabilization.

Avoid pulling or small-radius bending of the Input/Output fibers. Damage to the pigtails

can affect performance, loss, and the watertightness of the enclosure.

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4.2 Getting Started

The POS-002 is enabled by default, with control settings at their default values, when it is

powered on. The following steps describe the setup procedure:

1. The POS-002 has mounting holes at each corner of the enclosure. Use M3 screws

to anchor the module in place.

Figure 5 Mechanical drawing of POS-002 with mounting hole/screw information

2. Connect power source to power pins (PIN2: +12VDC; PIN3: GND; PIN4:

−12VDC). If the POS-002 is being installed as part of a larger system, make sure

that its ground is common with the ground for the rest of the system.

3. If the input optical power level is not known, measure it with an optical power

meter. Make sure that it is below 20 dBm (100 mW) for internal feedback units.

4. After verifying input optical power level, connect the input fiber to the input

connector of the POS-002. It is important to clean the fiber connector using

industry standard procedures. For a high power laser source, turn off optical

power source before connector cleaning.

5. If using external electrical feedback, connect the external feedback signal to the

POS-002. (PIN 8: DC error signal, PIN 9: GND).

Guidelines for electrical error signal:

Please note that there is no buffer between the input signal and the A/D converter.

To avoid damage to the A/D converter, the error signal should be within the

voltage limits listed below.

Feedback Signal Range:

Minimum Voltage Level 0.5 Volts

Maximum Voltage Level 4.5 Volts

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Hardware limits:

Conversion time per A/D sample 1.75 µS (max)

Acquisition Time 0.25 µS (min)

Maximum Sampling Rate 500 kHz

6. Turn on the DC power supplies. The POS-002 is enabled by default and will

begin operation on power-up.

7. After the input fiber is connected and the optical power is turned on, the POS-002

will automatically stabilize the input SOP to a linearly polarized output SOP

(internal optical feedback option) or optimize the SOP to either maximize or

minimize the error signal (external electrical feedback option). Note: The standard

version uses a maximum search algorithm. Minimum search may be available by

special request.

8. When SOP stabilization is not needed, such as in a system performance

comparison using stabilized and unstabilized input SOPs, the POS-002 can be put

into standby (disabled) mode via an RS-232 command (see section 4.4 for

details).

9. See section 4.4 for a description of the basic operation cycle and instructions on

customizing the setup.

4.3 Testing and Characterization:

The POS-002 can be serviced only by manufacturer-authorized personnel. There are no

user serviceable components in this system.

The performance of the POS-002 can be tested with standard polarization measurement

instruments or a laboratory setup. The output SOP from the POS-002 can be monitored

by a commercial polarization analyzer. For laboratory testing, the user can insert a

manual or motorized polarization controller before the input fiber connector, and connect

the output fiber to an optical power meter or photodetector. If the POS-002 being tested

has the SM output fiber option, a polarizer should be inserted between the output fiber

connector and optical power meter. Once the POS-002 is activated, the optical power to

the power meter or photodetector will be stabilized, independent of any adjustment of the

input polarization controller.

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4.4 Remote control and programming:

The POS-002’s active tracking can be enabled/disabled, and its operation parameters

changed, via remote control. While tracking is disabled, the POS-002 remains in the

setting at which it was disabled.

4.4.1 RS-232 Connection

The RS-232 serial interface port allows the user to remote control the POS-002 by

sending ASCII commands. The LabView test program provided with the POS-002 shows

a programming example.

The POS-002’s RS-232 communication pins are located next to its power pins (see

Figure 4 and Table 1).

Communication pins on POS-002:

PIN5: GND

PIN6: RXD

PIN7: TXD

Connect the communication pins to the RS-232 port of a computer or other control signal

source (see Figure 6 for correspondence between the POS-002 communication pins and

the DB9 connector on the connection cable). The POS-002 comes with two connection

cables. One has a 10-pin connector on one side to connect to the POS-002. On the other

side of that cable are labeled wires for the power and external signal connections, and a

3-pin connector to connect to the RS-232 connection cable. The RS-232 connection cable

has a matching 3-pin connector on one side to connect to the first cable, and a DB9

connector on the other side to connect to the RS-232 port of a computer. The pin

correspondence for the DB9 connector is shown below, where the numbers in

parentheses are the corresponding pin numbers on the POS-002.

GND (5)

6789

12345

TXD (7)

RXD (6)

Figure 6 RS-232 connector pin assignment for POS-002.

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4.4.2 Remote operation and commands

General Photonics provides a test program for remote control of the POS-002. See

section 4.4.4 for installation and operation instructions for the program.

The following steps and commands are recommended for remote operation of the POS-

002 using the RS-232 communication port.

1. Connect POS-002 to PC using provided cables.

2. Make sure that the RS-232 port settings on the control computer are as follows:

a. Baud rate: 9600 bps

b. Framing: asynchronous

c. Data bits:8

d. Parity bit: None

e. Stop bit: 1

f. Flow control: None

3. Power on the POS-002 by supplying DC ± 12V.

4. Make sure that the COM port number setting for the communications program

used to send the commands matches the COM port connected to the POS-002.

5. Referring to Table 2 below, send a command string (e.g. “*IDN?”) to the POS-

002 through the RS-232 port. There are many programming languages that

support serial communications, including Visual Basic, LabView and C.

Table 2 RS-232 Command List:

Query Commands

Command Description Response

*IDN? Query the Product Number. *IDN GP-POS-002V2.0-E#

*VER? Query the Firmware Version. *VER POS002-V21-

020513A#

(version dependent)

*MOD? Query operation status. *MOD ENA# POS enabled

*MOD DIS# POS disabled

*SER? Query serial number *1047000004xx#

Control Commands

*ENA# Enable polarization tracker. *E00#

*DIS# Disable polarization tracker. *E00#

Setup Commands

*FUN? Query current tuning mode. “Variable” or “Fixed”

*VAR# Set tuning mode to “variable step size”. *E00#

*FIX# Set tuning mode to “fixed step size”. *E00#

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*STS xx# Set step size.

Corresponding angle change = xx*0.22°

on Poincaré Sphere.

Range: 1 ~ 75.

Default value: 8

“Step Size = xx”

*STS? Query current step size setting. “Step Size = xx”

*AVG xx# Set AD average number

Corresponding increase in control loop

cycle time = (xx−1)* 2µs.

Range: 1 ~ 20.

Default value: 4

“AD AVG = xx”

*AVG? Request current AD average number “AD AVG = xx”

*THH xx# Set response threshold level

(sensitivity to noise and polarization

change).

For 0~5V feedback signal,

noise threshold = xx*1.22mV.

Range: 0 ~ 150.

Default value: 0

“Threshold = xx”

*THH? Query current threshold level. “Threshold = xx”

*DLY xxx# Set additional delay per step.

Intrinsic step time is 26µs.

The DLY command adds a delay offset to

this to slow down the effective step time.

Delay offset = 0.5*xxx µs.

Range: 0 ~ 59999.

Default value: 5

“*Delay = xxx”

*DLY? Query current delay offset. “*Delay = xxx”

Table 3 Command Response Codes:

E00 No error (Correct command received)

E01 Undefined Command

E02 Missing start character

E03 Missing end character

E04 Missing parameter

E05 Invalid syntax found in command string

E06 Invalid mode command.

E07 String of characters too long(>buffer limit)

E08 Light power too high

E09 Light power too low

E10 parameter outside allowed range

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RS-232 command notes:

1. Only one command is allowed in each command string.

2. The POS-002 will respond to a command with either the requested data,

formatted as described in Table 2, or with one of the response codes listed in

Table 3. While the POS-002 is processing a command and sending back a

response ASCII code, any additional commands sent by the computer will be

ignored.

Basic Operation and Control Parameter Definitions:

A POS-002 using the maximum search algorithm tunes the output state of polarization

(SOP) to maximize a feedback signal. This can be an internal reference (POS-002-I) or a

0-5V analog electrical feedback signal provided by the user (POS-002-E). Each time it

runs through its control cycle, the POS-002 checks the feedback signal and, if necessary,

makes a polarization adjustment.

Figure 7 POS-002 response to discontinuous change in input polarization state

(using default control settings and fixed step size mode)

Figure 7 shows the response of the POS-002 to a single discontinuous change in the input

polarization state, using the default control parameter settings. The red line is the input

polarization, and the blue line is the POS-002 output. The POS-002 compensates for the

input polarization change via a series of small polarization steps.

The labeled quantities on the graph are as follows:

A: Step time: With settings delay = 0, AD Avg. = 1, each step takes 26µs.

B: Step size: At step size = 8, the angle change per step ≈1.76°on the Poincaré

sphere.

C: Output signal fluctuation: The active SOP searching causes a baseline level of

fluctuation around the target SOP.

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The control parameters allow the user to optimize the POS-002 control cycle for the

requirements of particular applications. Their effects on the quantities described above

will be explained in the following sections.

Note: The POS-002 does not store user-selected settings in its permanent memory.

After it is powered off, all control parameters will revert to the default settings.

Polarization Tuning Modes

The POS-002 has two polarization tuning modes: variable and fixed step size. The default

mode is variable step size. In this mode, the POS-002 dynamically adjusts the step size

that it uses within a range of one to six times the step size set by the most recent *STS

xx# command. This allows it to react quickly, using a larger step size, when the SOP is

far from the target, and then to use a smaller step size closer to the target to smooth out

the response.

In fixed step size mode, the POS-002 uses a constant step size, set using the *STS xx#

command, for its polarization adjustments.

The *VAR# and *FIX# commands are used to select variable and fixed step size modes,

respectively, and the *FUN? command is used to query the current operation mode.

Control Parameters

The setup commands in the command list are used to set or to request the current values

of the control parameters for the feedback control loop.

-Command: *STS xx#

The step size defines the control voltage increment applied to the polarization controller

per control loop cycle in response to a change in feedback signal level. The POS-002 uses

a 0V~150V voltage output to control the polarization controller. This control voltage

range is converted to 212 = 4096 digital steps for the purposes of the control algorithm. 1

digital step = 150V/4096 = 0.0366V ≈0.2°on the Poincaré sphere. The *STS xx#

command therefore sets the voltage output step size to xx * 0.0366V, and the

corresponding polarization step on the Poincaré sphere to approximately xx * 0.2°.

The default setting is 8, corresponding to a control voltage step of 8 * 0.0366V, which

results in a maximum polarization change of about 1.76° on the Poincaré sphere. In fixed

step size mode, this step size remains constant at the selected value. In variable step size

mode, the set value is used as the base step size when the POS-002 begins polarization

adjustment.

The following figures illustrate the effects of step size selection. For easier illustration,

the measurements were taken with the POS-002 in fixed step size mode.

Document #: GP-UM-POS-002-21 Page 17 of 30

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Figure 10 shows the POS-002 output polarization vs. time in response to a discontinuous

change in input polarization, using the default step size setting.

If a smaller step size is chosen, the resulting output polarization will be smoother, but

more steps are needed to compensate for a given amount of input polarization change.

Figure 8 shows the POS-002 output polarization vs. time in response to a discontinuous

change in input polarization, using a step size setting smaller than the default value.

Figure 8 POS-002 output, reduced step size Figure 9 POS-002 output, step size = default

Choosing a larger step size will reduce the response time, but can also increase noise.

Figure 10 shows the response of the POS-002 to the same discontinuous change in the

input polarization state as in Figure 7, but with a low threshold setting and a step size

setting larger than the default value. Compared to Figure 7, the total recovery time is

smaller, but the output polarization fluctuation (labeled C in Figure 7) increases.

Figure 10 POS-002 response to discontinuous change in input polarization state

(step size larger than default setting)

Document #: GP-UM-POS-002-21 Page 18 of 30

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If the optical signal is relatively stable, with changes occurring on a long time scale, a

smaller step size can yield better results. A larger step size is better for dealing with a

quickly changing input polarization.

-Command: *DLY xxx#

The intrinsic time required per control cycle is about 26µs. However, for some

applications, a slower cycle time may be needed. For example, the optical signal

sampling used to generate the feedback signal may be done at a location far away from

the POS-002, or the electronics used to generate the feedback signal may need time to

respond to polarization changes made by the controller. The DLY command adds a delay

offset to the period between a polarization controller step and the next read of the

feedback signal, increasing the effective cycle time to 26 + 0.5*xxx + 2*(yy −1) µs,

where xxx is the delay setting and yy is the AD average setting.

Figure 11 POS-002 output, delay = 100 Figure 12 POS-002 output, delay = 0

Figure 13 POS-002 response to discontinuous change in input polarization state

(delay = 50)

Document #: GP-UM-POS-002-21 Page 19 of 30

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Figure 13 shows the response of the POS-002, using a delay setting of 50, to the same

discontinuous change in the input polarization state used in Figure 7. It can be seen that

the time per step, and thus the cumulative response time, is longer. Figure 11 and 12

provide a closeup comparison of the response time with different delay settings.

-Command: *AVG xx#

During each control loop cycle, the POS-002 performs one adjustment (step) to the

polarization control voltage, checks the AD feedback once and compares it with a

reference value to decide its action for the next cycle. For an external feedback model,

the quality of the feedback signal is the limiting factor in device performance. Any noise

in the feedback signal will be read as input polarization change and will therefore result

in output polarization fluctuation.

The AD average number defines the number of AD samples averaged to obtain the

feedback signal value used for one control loop cycle. Increasing the AD average number

can improve the stability if the feedback signal is noisy. For example, setting AD avg. = 2

converts a 50mV, 10KHz noise component in the feedback signal to a 25mV, 5KHz noise

component.

Increasing the AD average number also increases the control loop cycle time by the

amount specified in the table.

Figure 14 shows the response of the POS-002, using a larger AD average than the default

setting, to the same discontinuous change in the input polarization state used in Figure 7.

The output polarization fluctuation (labeled C in Figure 7) is much smaller than in Figure

7.

Figure 14 POS-002 response to discontinuous change in input polarization state

(AD average larger than default setting)

Document #: GP-UM-POS-002-21 Page 20 of 30

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网址：www.bonphot.com

邮箱：[email protected]

电话：0512-62828421

General Photonics POS-002 User manual

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