THORLABS TLX1 User manual

TLX1 / TLX2
Tunable Laser Sources
C-Band / L-Band
User Guide

TLX Series of Tunable Laser Sources
Table of Contents
Chapter 1 Introduction.......................................................................................................................... 1
1.1. Parts List..........................................................................................................................1
1.2. Block Diagram.................................................................................................................1
1.3. Front and Rear Panel Overview .....................................................................................2
Chapter 2 Safety .................................................................................................................................... 3
2.1. Precautions......................................................................................................................4
Chapter 3 Quick Start Guide................................................................................................................ 5
3.1. Hardware Set-up..............................................................................................................5
3.2. Controls on the Home Page ...........................................................................................6
3.3. Controls in the Settings Pages ......................................................................................7
Chapter 4 Operating Instructions........................................................................................................ 8
4.1. Laser Settings Page........................................................................................................8
4.2. Variable Optical Attenuator Settings Page .................................................................10
4.3. Load Page......................................................................................................................11
4.4. Menu Page .....................................................................................................................12
Chapter 5 Specifications .....................................................................................................................15
5.1. Laser Specifications .....................................................................................................15
5.2. General Specifications..................................................................................................15
5.3. Power and Environmental Specifications...................................................................16
Chapter 6 Control & PC Connections................................................................................................17
6.1. General Purpose I/O, RS-232, and USB Connections................................................17
6.2. The Laser Safety Interlock............................................................................................18
Chapter 7 Mechanical Drawings.........................................................................................................19
Chapter 8 Maintenance, Repair & Fuses...........................................................................................20
8.1. Maintenance & Repair...................................................................................................20
8.2. Replacement Parts........................................................................................................20
8.3. Replacing the Main Fuse ..............................................................................................21
Chapter 9 Troubleshooting.................................................................................................................22
Chapter 10 Declaration of Conformity.................................................................................................23
Chapter 11 Thorlabs Worldwide Contacts..........................................................................................24

TLX Series of Tunable Laser Sources Chapter 1: Introduction
Rev C, February 21, 2020 Page 1
Chapter 1 Introduction
The emission wavelength of the TLX Series of tunable laser sources can be swept over commonly used
telecommunication wavelength ranges. The TLX1 emits in the C-band, while the TLX2 emits in the L-band. The
optical output has a narrow typical linewidth of 10 kHz, and operation with the frequency dither option stabilizes
the laser wavelength. The wavelength tuning resolution is 50 GHz. Complete control over the optical output power
is provided by the built-in variable optical attenuator, which can operate in Constant Attenuation or Constant
Power modes.
The instrument can be controlled in two ways. The simplest method is directly via the built-in graphical user
interface (GUI) and touchscreen. The instrument can also be operated remotely via the RS-232 or USB ports on
the back panel. Remote control is enabled using simple SCPI-type serial commands from a PC. See the remote
control user guide (RCUG), which can be downloaded from https://www.thorlabs.com/manuals.cfm, for details.
The most recent firmware and remote control software tool can be downloaded by visiting
https://www.thorlabs.com/navigation.cfm?Guide_ID=2191 and entering the Item # into the search field.
Thorlabs’ technical support can provide up-to-date information on available firmware revisions and control
functions. NOTE: This manual covers both the TLX1 and TLX2 models, as their architectures are very similar.
Only the wavelength bands are different. Their differences are clearly noted in the following sections.
1.1. Parts List
Inspect the shipping container for damage. If the shipping container seems to be damaged, keep it until you have
inspected the contents and tested the unit mechanically and electrically. Verify that you have received the
following items within the package:
1. TLX1 or TLX2 Tunable Laser Source
2. Power Cord According to Local Power Supply
3. PM Loopback Fiber Optic Cable
4. Interlock Keys
5. 2.5 mm Interlock Pin (Pre-installed in back panel)
6. 1.25 A, 250 VAC Fuse
7. USB Type A to Type B Cable, 6’ Long
1.2. Block Diagram
These instruments contain both the laser source and a variable optical attenuator for output power control. The
user can also choose to use an external laser source of their own by attaching directly to the Laser Input port
instead of using the supplied loop-back fiber patch cord. The Laser In port uses PM fiber with light linearly
polarized along the slow axis as shown on the front panel. Maximum input power is 20 dBm (100 mW). Optical
power is monitored in two places (Mon) for the purpose of enabling bias output power control. These power
values are also available at the I/O port on the rear panel.

TLX Series of Tunable Laser Sources Chapter 1: Introduction
Page 2 TTN093744-D02
1.3. Front and Rear Panel Overview
Label
Description
Detail
A
Touchscreen display
B
Adjustment knob
C
Key Switch and Indicator
E
Laser Output
PM FC/PC
F
VOA Input
PM FC/PC
G
VOA Output
PM FC/PC
M
Standby Button
N
I/O Port
HD DB-15
O
Option Label
P
RS-232 Port
DB-9
Q
USB Port
Type B
R
Laser Interlock
2.5 mm jack
S
Power Connector
T
Fuse Tray
U
Power Switch
B
A
C
M
E
F
G
R
P
N
S
O
T
U
Q

TLX Series of Tunable Laser Sources Chapter 2: Safety
Rev C, February 21, 2020 Page 3
Chapter 2 Safety
All statements regarding safety of operation and technical data in this instruction manual will only apply when the
unit is operated correctly. If equipment is used in a manner not specified by the manufacturer, the protection
provided by the equipment may be impaired. Only with written consent from Thorlabs may changes to single
components be carried out or components not supplied by Thorlabs be used
Warning: Risk of Electrical Shock
Before applying power to the instrument, make sure that the protective conductor of the 3 conductor mains power
cord is correctly connected to the protective earth contact of the socket outlet. Improper grounding can cause electric
shock with damage to your health or even death. Only use mains cable with sufficient current and voltage ratings
for this instrument. The local supply voltage must be in the range specified on the rear panel, and the correct fuse
must be installed in the fuse holder. If not, please replace the main fuse (see Section 8.3). Do not position equipment
in a way that makes it difficult for the user to operate the disconnecting device. Do not remove covers. Refer servicing
to qualified personnel.
Warning: Risk of Explosion
The instrument must not be operated in explosion endangered environments.
Warning: Laser Radiation
Avoid Exposure –Radiation emitted from apertures. Do not look into the laser
aperture while the laser is on. Injury to the eye may result. Laser should not be turned
on unless there is an optical fiber connected to the laser output port.
Caution –Use of controls or adjustments or performance of procedures other than
those specified herein may result in hazardous radiation exposure.
Caution: ESD Sensitive Component
The components inside this instrument are ESD sensitive. Take all appropriate precautions to discharge personnel
and equipment before making any connections to the unit. A front panel grounding jack is provided for connection to
a wrist strap.
Caution: Components not Water Resistant
This instrument should be kept clear of environments where liquid spills or condensing moisture are likely. It is not
water resistant. To avoid damage to the instrument, do not expose it to spray, liquids, or solvents.
Caution: Follow Intended Usage Guidelines
This product is not suitable for household room illumination.
Inputs and outputs must only be connected with shielded connection cables.
Do not obstruct the air ventilation slots in housing.
Mobile telephones, cellular phones or other radio transmitters are not to be used within the range of three meters of
this unit since the electromagnetic field intensity may then exceed the maximum allowed disturbance values
according to IEC 61326-1.

TLX Series of Tunable Laser Sources Chapter 2: Safety
Page 4 TTN093744-D02
2.1. Precautions
The following statement applies to the products covered in this manual, unless otherwise specified herein. The
statement for other products will appear in the accompanying documentation.
Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to
part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference
in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation.
This product has been tested and found to comply with the limits according to IEC 61326-1 for using connection
cables shorter than 3 meters (9.8 feet).
Thorlabs is not responsible for any radio television interference caused by modifications of this equipment or the
substitution or attachment of connecting cables and equipment other than those specified by Thorlabs. The
correction of interference caused by such unauthorized modification, substitution or attachment will be the
responsibility of the user. The use of shielded I/O cables is required when connecting this equipment to any and all
optional peripheral or host devices. Failure to do so may violate FCC and ICES rules.
This precision device should only be shipped if packed into the complete original packaging including the custom
cut foam padding. If necessary, ask for replacement packing material.

TLX Series of Tunable Laser Sources Chapter 3: Quick Start Guide
Rev C, February 21, 2020 Page 5
Chapter 3 Quick Start Guide
3.1. Hardware Set-up
For first use, plug the main power cable into the rear panel connector, and then plug the other end into an AC wall
receptacle. Flip the power switch on the rear panel to the ON (I) position. The unit will now be in the “Standby”
mode, and the front panel standby button should glow amber.
Attach the PM loopback fiber optic cable between the Laser Out and Laser In FC connectors on the front panel.
Be sure to clean both ends of the fiber as described in the Maintenance Section of this manual.
Insert the key into the interlock switch and turn it towards the unlock symbol ( ). This allows the laser to be
turned on, but the LASER ON indicator will not glow green until the laser is actually turned on by using the
touchscreen interface. Turn on the unit by pressing the amber standby button on the front panel which will then
turn green to indicate the unit is fully on. The touchscreen display will come up with a boot screen for about 5
seconds and then go to the home page. The unit will initialize in the factory default state with all functions OFF.

TLX Series of Tunable Laser Sources Chapter 3: Quick Start Guide
Page 6 TTN093744-D02
3.2. Controls on the Home Page
The TLX1 can be fully controlled by using the resistive touchscreen display for all functions. You can use a finger
or a plastic stylus to make selections on the screen. In addition, the knob on the front panel can be used in place
of the on-screen arrow buttons for quickly changing set-point values. Pressing (clicking) the knob will confirm a
new set-point value.
The Home screen (or dashboard) is organized into three main sections.
The left side contains the ON/OFF buttons for each of the main instrument functions. Tapping either of these buttons
will toggle the function on and off. The same ON/OFF functionality is also available on the individual Settings pages.
The power buttons turn green to indicate the function is ON, and turn red to indicate the function is disabled.
The central section is the main dashboard for reporting operational values of each section. Tapping the screen in
this middle area will take the user to the corresponding Settings page for each section. Note that the green dot in
each of these sections indicates the function is stable. A blinking green dot indicates the function is still stabilizing.
The right side of the screen provides access to the main utility functions of the box.
The screenshot below shows some of the common warning indicators on the HOME page. Some functions can
be disabled when the laser power is low. In this case, buttons may be disabled and warnings indicators may
appear.
Tap these buttons
to turn functions
ON or OFF
Tap in these areas
to go to the related
Settings pages
Blue button
Utility functions
Green Dot
Stability Indicator
Power units (dBm or
mW) are set in the
VOA Settings page
Disabled
Function
Low Power
Warnings
Interlock
Warning

TLX Series of Tunable Laser Sources Chapter 3: Quick Start Guide
Rev C, February 21, 2020 Page 7
3.3. Controls in the Settings Pages
The Settings pages all follow the same general design and functionality as shown in the example screenshot
below. The upper section with white letters displays the parameters that can be changed. Simply tap on the
parameter of interest to highlight it, and the controls for that parameter will be presented.
The lower section with amber letters displays selected values that are convenient to monitor on that page.
The right-hand column provides the controls for changing the values for the selected parameters. The main
control knob on the front panel can also be used to adjust and confirm selected values. The screenshots below
show examples of the touchscreen controls.
Tap to select parameter
Yellow highlight will appear
Increase value
Decrease value
Change Step Size
Confirm new value
Cancel any changes
Monitor area
MIN / MAX warnings
indicate that the setting
limit for a particular
parameter has been
reached.

TLX Series of Tunable Laser Sources Chapter 4: Operating Instructions
Page 8 TTN093744-D02
Chapter 4 Operating Instructions
4.1. Laser Settings Page
To access the Laser Settings page, tap on the Laser monitors pane on the Home page. Here the user can
control the laser wavelength and choose whether or not to use the dither feature (available for transmitters
with C-band or L-band lasers only) to stabilize the wavelength. Turning the dither off will result in lower
phase and intensity noise, but the wavelength may driftslightly over time. The monitors onthis page provide
live readings of many parameters.
Caution: The laser should not be turned on unless there is an optical fiber connected to the laser output port.
Optical frequency can be set at increments of 50 GHz; these lasers also support a fine tuning frequency offset
feature, allowing the frequency to be adjusted by an offset from -30.000 GHz to +30.000 GHz. The ITU channel
number on these pages is an index number given only for convenience, which is unique to this instrument; actual
frequencies and spacings are specified by the ITU standard.
To adjust the ITU channel, tap on the ITU CHANNEL row and use the arrow buttons to increment or decrement
the channel. Press the green check mark to accept the new channel, or the red cancel button to abort the change.
You may also use the adjustment knob. Note that you are initially editing by channel, as indicated by the STEP
CHAN button. Note that the frequency and wavelength value are estimated based on the laser’s nominal 50 GHz
channel spacing, not measured by the instrument.
To apply a fine-tuning frequency offset, tap the STEP CHAN button. The button will cycle to the next mode, STEP
10GHz. In this mode, using the up or down arrows or control knob will adjust the most significant digit of the
frequency offset. Tapping the button repeatedly will cycle through the STEP 1GHz, STEP 100MHz, STEP 10MHz,
and STEP 1MHz modes, allowing you to edit the offset in finer units of 1GHz, 100MHz, 10MHz, or 1MHz. Tapping
the button one more time will cycle back to STEP CHAN mode.
Tap here to change the laser
wavelength
Calculated frequency and
wavelength are displayed in
the monitor section.
Tap here to change the STEP size

TLX Series of Tunable Laser Sources Chapter 4: Operating Instructions
Rev C, February 21, 2020 Page 9
Note that while these lasers can have their frequency adjusted by increments as small as 1 MHz, the laser’s actual
tuning accuracy is not this fine. See Section 5.1 below for more information.
To turn the dither setting on or off, tap on the DITHER row and use the ON or OFF buttons to change the setting,
or the red cancel button to abort the change.
The plot below shows laser frequency noise as a function of optical frequency when the laser is operated with and
without dither enabled. The red trace shows low noise operation when dither is turned off. Wavelength stability is
improved by operating with dither, but the blue trace shows that this comes at the expense of added noise.
Use these buttons to toggle the
dither function On/Off
FM Noise Spectrum with and without dither.
Wavelength stability is improved with dither,
but at the expense of adding noise (blue line).
Red line show Low Noise operation with
dither turned off.
In "STEP 1GHz" mode you can
edit the fine-tuning frequency
offset in steps of 1 GHz.

TLX Series of Tunable Laser Sources Chapter 4: Operating Instructions
Page 10 TTN093744-D02
4.2. Variable Optical Attenuator Settings Page
To get to the Variable Optical Attenuator (VOA) Settings page tap in the VOA monitors pane on the Home page.
The VOA provides the means for adjusting and stabilizing either the attenuation or the output power.
Note that the power measurement units for the entire interface are set on this page.
The VOA can operate in either of two modes: 1) Constant Attenuation, or 2) Constant Output Power.
Constant Attenuation Mode maintains a fixed attenuation level between the output of the laser and the output of
the VOA. Any fluctuations at the input are transferred to the output.
Constant Output Power Mode acts as a stabilizer by holding the final optical power constant independent of input
fluctuations (within controllable limits such as input power and attenuation).
Tap here to change Modes
Tap here to select Constant
Attenuation mode
Tap here to select Constant
Output Power mode
Not enough power to reach the
set point
VOA in Constant Output Power
mode
Tap here to adjust output
power
Loss of VOA calibration due to
low power
Tap here to change units for
power measurement
VOA in Constant
Attenuation mode
Tap here to change attenuation
level

TLX Series of Tunable Laser Sources Chapter 4: Operating Instructions
Rev C, February 21, 2020 Page 11
4.3. Load Page
To get to this page, tap the blue Load button on the Home page. The Load page allows the user to revert back to
the factory default settings. Future firmware revisions will have the ability to store and load instrument states
defined by the user.
Tap to restore factory settings
Confirm or Cancel the return to
factory default settings

TLX Series of Tunable Laser Sources Chapter 4: Operating Instructions
Page 12 TTN093744-D02
4.4. Menu Page
To get to this page, tap the blue Menu button on the Home page. The Menu page has links to several pages that
allow the user to control the display, sounds, lights, and get help information. The following sections describe
these functions in more detail.
4.4.1. Display and Sound Settings Page
Path here: Home > Menu > Display & Sounds.
DISPLAY BRIGHTNESS controls the overall brightness of the touchscreen display
DISPLAY SLEEP TIME controls how long the the touchscreen display is visible before it sleeps
BUTTON CLICK toggles the sound produced when tapping buttons (On/Off)
NOTIFICATION BEEP toggles the sound associated with certain on screen notifications (On/Off)
Tap here to find help from
Thorlabs Technical Support
Tap here to control the accent
LEDs that emanate from the
bottom of the instrument
Tap here to find system info
Tap here to control the
touchscreen and the
sounds it makes
Tap any of the fields to reach
their controls

TLX Series of Tunable Laser Sources Chapter 4: Operating Instructions
Rev C, February 21, 2020 Page 13
4.4.2. System Information Page
Path here: Home > Menu > System Information.
The System Information page displays the installed hardware and software versions
4.4.3. Accent LED Settings Page
Path here: Home > Menu > Accent LEDs
The accent LED settings control the intensity of the color LEDs that emanate from the bottom of the instrument.
These can be used for a variety of purposes. Their primary function, however, is to look cool. You can set them to
your favorite color.
This is useful information when
in need of technical support or to
verify firmware revisions
Tap any of the three color fields to
access the up/down controls.
Learn to mix colors!

TLX Series of Tunable Laser Sources Chapter 4: Operating Instructions
Page 14 TTN093744-D02
4.4.4. Thorlabs Help Page
Path here: Home > Menu > Thorlabs Help
The Thorlabs Help page displays the Tech Support phone number, Thorlabs web site, and the installed hardware
and software versions. This information will be useful when speaking with Tech Support.

TLX Series of Tunable Laser Sources Chapter 5: Specifications
Rev C, February 21, 2020 Page 15
Chapter 5 Specifications
All Specifications are at 1550 nm and 25 °C ambient temperature, unless otherwise noted. C-band specifications
apply to the model TLX1, and L-band specifications apply to the model TLX2.
5.1. Laser Specifications
5.2. General Specifications
Parameter
Value
Unit
Min
Typ.
Max
Optical Output Power
dBm
12.5
13.5
14.5
Frequency Range (C-band)
THz
191.5
-
196.25
Wavelength Range (C-band)
nm
1527.6
-
1565.5
Frequency Range (L-band)
THz
186.35
-
190.95
Wavelength Range (L-band)
nm
1570.0
-
1608.8
Frequency Accuracy
GHz
-1.5
-
1.5
Tuning Resolution
GHz
-
50
-
Tuning Speed (Between Wavelengths)
S
-
10
-
Fine Tuning Resolution
MHz
-
1
-
Fine Tuning Speed
GHz/s
-
1
-
Fine Tuning Range
GHz
-30
-
30
Side Mode Suppression Ratio (SMSR)
dB
40
55
-
Optical Signal Noise Ratio (OSNR)
dB
40
60
-
Intrinsic Linewidth
kHz
-
10
15
Relative Intensity Noise (RIN)
dB/Hz
-
-
-145
Back Reflection
dB
-
-
-14
Polarization Extinction Ratio
dB
18
-
-
Parameter
Typical Values
Notes
Optical Input Power
20 dBm Max
22 dBm Abs. Max
External Laser Wavelength Range
1525 nm –1610 nm
Optical Insertion Loss
0.7 dB Typical
Laser IN to Optical OUT
Power Monitors Accuracy
±0.5 dBm
@ 1550 nm
Power Monitors Resolution
0.01 dBm
VOA Response Time
1 s

TLX Series of Tunable Laser Sources Chapter 5: Specifications
Page 16 TTN093744-D02
5.3. Power and Environmental Specifications
Parameter
Min
Max
Main AC Voltage
100 VAC
250 VAC
Power Consumption
-
60 VA
Line Frequency
50 Hz
60 Hz
Operating Temperature
10 °C
40 °C
Storage Temperature
0 °C
50 °C
Relative Humidity1
5%
85%
1
Non-Condensing Environment

TLX Series of Tunable Laser Sources Chapter 6: Control & PC Connections
Rev C, February 21, 2020 Page 17
Chapter 6 Control & PC Connections
6.1. General Purpose I/O, RS-232, and USB Connections
The back panel has connectors for monitor and control functions, as well as for upgrading the firmware. Both the
RS-232 and the USB connections can be used for remotely controlling the TLX series lasers via SCPI type serial
commands. Which connector to choose for remote control operation depends on the demands of the application
and the user’s preference. See the remote control user guide (RCUG), which can be downloaded from
https://www.thorlabs.com/manuals.cfm, for information about the commands and connecting the laser to a PC.
The most recent firmware and remote control software tool are available through Thorlabs’ website: visit
https://www.thorlabs.com/navigation.cfm?Guide_ID=2191 and enter the Item # into the search field. The
laser’s firmware can be updated by uploading the new version from a PC via the USB port. Thorlabs’ technical
support can provide up-to-date information on available firmware revisions and control functions.
The 15-pin I/O connector provides outputs from the power monitors in the optical path (see the block diagram in
Chapter 3). The power monitors provide a voltage that is proportional to the optical power with one of two gain
settings. These values are available on the I/O DB15 connector. The gain setting for each monitor is determined
by software, and reported on the corresponding Gain Indicator pins. 0.0 V indicates Low Gain (40 V/W) and 3.3 V
indicates High Gain (4000 V/W). Maximum output voltage at the monitor pin is less than 12 V (into a high
impedance). Power monitor bandwidth is limited to about 150 Hz.
I/O Conn.
Pin #
Description
RS-232
Pin #
Description
HD DB15
1
Reserved for Future Use
DB9
1
N/C
HD DB15
2
Power Monitor 2
DB9
2
RS232 Input
HD DB15
3
Power Monitor 3
DB9
3
RS232 Output
HD DB15
4
Reserved for Future Use
DB9
4
N/C
HD DB15
5
Analog Ground
DB9
5
Digital Ground
HD DB15
6
Analog Ground
DB9
6
N/C
HD DB15
7
Analog Ground
DB9
7
N/C
HD DB15
8
Analog Ground
DB9
8
N/C
HD DB15
9
Analog Ground
DB9
9
N/C
HD DB15
10
Analog Ground
HD DB15
11
Reserved for Future Use
HD DB15
12
Reserved for Future Use
HD DB15
13
Reserved for Future Use
HD DB15
14
Mon 2 Gain Indicator
HD DB15
15
Mon 3 Gain Indicator