Butterfly Laser Diode Mounts

  • Zero Insertion Force (ZIF) Sockets
  • Easy Integration with Thorlabs’ Current & TEC Controllers
  • Compatible with One & Two Port Devices


Universal 14-Pin Butterfly Laser Diode Mount


Additional User-Configurable Pin-Out Card
(One Included with LM14S2)

LM14S2 Shown with a Two-Port
Electro-Optic Device

Related Items

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Feature Comparison of Butterfly Laser Mounts
Item # LM14S2a LM14TSb CLD1015c
Supports Type 1 (Anode GND)
Supports Type 2 (Anode GND)
Supports Bias-T Connection - -
Supports Thorlabs ULN Laser - -
Integrated Laser-Case-Temperature Stabilization - -
DB9 Input for Thorlabs' Laser Driver -c
DB9 Input for Thorlabs' Laser-Chip TEC Controller -c
Dedicated ULN FBG TEC Controller Input - -
  • The LM14S2 is a butterfly laser diode mount that also supports two-port devices and Bias-T connections.
  • The LM14TS is an active, low-noise butterfly mount with integrated laser case TEC.
  • The CLD1015 is a compact laser diode driver with a TEC and mount for butterfly packages.


  • Laser Diode Mount for 14-Pin Butterfly Packages
  • Zero Insertion Force (ZIF) Mounting Socket
  • Type 1, Type 2, Type 2 with Bias-T, and User-Defined Pinout Configurations
  • LED Indicates When Laser is Enabled

The LM14S2 Universal 14-Pin Butterfly Laser Diode Mount is designed for use with lasers, optical amplifiers, and two-port electro-optic devices in a 14-pin type 1, 2, or 2 with bias-T butterfly package. The top surface has heat sink fins and a recessed region to mount the laser diode, resulting in a low profile package with a temperature coefficient of 3 °C/W. The LM14S2 also includes a laser diode TEC lockout featurea that disables the laser when the TEC controller is not active. The LM14S2 supports maximum laser and TEC currents of 5 A each. In order to utilize the TEC controller, the laser must have an integrated thermoelectric cooler (TEC) or thermistor sensors. This mount also features a zero insertion force (ZIF) socket, a remote safety interlock connection, and an LED to indicate that the laser diode is enabled.

The LM14S2 eliminates the restriction of fixed-pin configuration mounts by using exchangeable configuration cards that plug into a connector located on the bottom of the mount. Included with the LM14S2 is a card that provides compatibility with both type 1 pump laser diodes and type 2 telecom laser diodes. For the pin diagrams that correspond to these types, please refer to the Pin Diagrams tab. In addition, a second card (Item # LM14S2-UA) is also included. The LM14S2-UA is a user-configurable card designed to allow custom wiring of the mount. Additional LM14S2-UA user-configurable cards are available separately. Please note that even with an LM14S2-UA, only anode-grounded diodes can be used with the LM14S2 butterfly laser mount.

In addition to the configurable pinout feature, a bias-T adapter is included, allowing for RF modulation of butterfly lasers specifically designed with this capability. It features a female SMA connector for an RF source up to 500 MHz, and is designed for lasers with a type 2 pin configuration including an internal bias-T and built-in blocking inductor. For more details on the pin assignments, please refer to the Pin Diagrams tab as well as the spec sheet for the specific laser diode to be used. Please note that Thorlabs' butterfly package laser diodes are not compatible with the bias-T adapter.

The LM14S2 is pin-for-pin compatible with all of Thorlabs' benchtop laser diode and TEC controllers, and most of our platform laser and TEC controllers as well, eliminating the need for custom-made interface cables. Thorlabs also manufactures customized, application-specific butterfly mounts for OEM customers. Please see the OEM Modules tab for details.

  • The TEC lockout feature only functions with Thorlabs' laser and TEC controllers, and can be easily bypassed if not required.
Item #LM14S2
Maximum Laser Current5 A
Polarity of Laser DiodeAnode Ground
Polarity of Monitor DiodeFloating
Maximum TEC Current5 A
Temperature SensorThermistora
Temperature Rangeb0 to 70 °C
Temperature Coefficient of Heat Sink3 °C/W
Dimensions3.50" x 3.50" x 1.31"
(88.9 mm x 88.9 mm x 33.3 mm)
Modulation (Bias-T Adapter) Specificationsc
RF Modulation Frequency100 kHz to 500 MHz
RF Input ConnectionSMA
RF Input Impedance25 Ω
RF Power (Max)200 mW or Limit of Laser Diode
  • At 25 °C with 2 A of TEC current, integrated into the laser package.
  • This is the temperature range supported by the LM14S2. Installed laser diodes may have different ranges.
  • The bias-T adapter is only compatible with Type 2 Telecom Laser Diodes (see the Pin Diagrams tab for details).

Laser Diode Connector

D-type Female

DB9 Female

Pin # Signal
1 Interlock and Status Pin (LDC Specific)
2 Photodiode Cathode PDC
3 Laser Diode Anode LDA
4 Photodiode Anode PDA
5 Interlock and Status Return
6 Laser Diode Voltage (-) VLD(-)
7 Laser Diode Cathode LDC
8 Not Used
9 Laser Diode Voltage (+) VLD(+)

Bias-T Modulation Adapter*

SMA Female


*RF input for modulation with an external source from 100 kHz to 500 MHz.

TEC Connector

D-type Male

DB9 Male

Pin # Signal
1 TEC Lockout (+)
2 +Thermistor TH+
3 -Thermistor TH_GND
4 TEC (+)
5 TEC (-) and TEC Lockout (-)
6 Not Used
7 Not Used
8 Not Used
9 Not Used

Pin Assignment of the 14-pin Sockets

The included LM14S2-US custom configuration card can be used for any other pin configuration. This card is also available separately below.

Pin to Connector Configuration for Type 1 Pin to Connector Configuration for Type 2 Pin to Connector Configuration for
Type 2 with Bias-T

Click to Enlarge

Click to Enlarge

Click to Enlarge
1 TEC Anode 1 Thermistor Ground 1 Thermistor Ground
2 Thermistor 2 Thermistor 2 Thermistor
3 PD Anodea 3 LD Cathode 3 LD Cathode
4 PD Cathodea 4 PD Anode 4 PD Anode
5 Thermistor Ground 5 PD Cathode 5 PD Cathode
6 N.C. 6 TEC Anode 6 TEC Anode
7 PD Cathodea 7 TEC Cathode 7 TEC Cathode
8 PD Anodea 8 Case 8 Case
9 LD Cathodeb 9 Case 9 Case
10 LD Anode, Ground 10 N.C. 10 N.C.
11 LD Cathodeb 11 LD Anode 11 LD Anode
12 N.C. 12 N.C. 12 Modulation Inputc
13 LD Anode, Ground 13 LD Anode 13 LD Anode
14 TEC Cathode 14 N.C. 14 N.C.
  • The monitor photodiode may be placed across either pins 7 and 8 or pins 3 and 4. Please refer to the Laser Diode's documents for the specific pin configuration.
  • The laser diode cathode may be placed at either pin 9 or pin 11. Please refer to the Laser Diode's documents for the specific pin configuration.
  • When Using the Bias-T Adapter PCB.
Custom Module for Two 14-Pin Butterfly Packages
Click to Enlarge

Custom Module for 14-Pin Butterfly Packages

Thorlabs OEM Manufacturing

In addition to manufacturing a wide variety of active optical devices, Thorlabs is equipped to deliver customized laser diode, superluminescent diode, and semiconductor optical amplifier modules in OEM quantities. For example, the module shown to the right provides temperature and current control for two superluminescent diodes (SLDs) from an SPI interface. Because this module is designed for standard 14-pin butterfly packages, it is easily adapted for combinations of other optical devices, such as a pigtailed semiconductor laser with an optical amplifier.

As a manufacturer of III-V semiconductor devices, MEMS-VCSEL lasers, quantum cascade lasers, lithium niobate optical modulators, and other devices, we are intimately familiar with the operating requirements of driving lasers and related components. Please visit this webpage for an overview of our laser manufacturing facility, or contact us directly to discuss your application's needs.

Contact Thorlabs Tech Support

LM14S2 SmartPack Packaging
Click to Enlarge

LM14S2 Packaging

Smart Pack

Item #% Weight
LM14S2 21.52% 30.10 kg

Smart Pack

  • Reduce Weight of Packaging Materials
  • Increase Usage of Recyclable Packing Materials
  • Improve Packing Integrity
  • Decrease Shipping Costs

Thorlabs' Smart Pack Initiative is aimed at waste minimization while still maintaining adequate protection for our products. By eliminating any unnecessary packaging, implementing packaging design changes, and utilizing eco-friendly packaging materials for our customers when possible, this initiative seeks to improve the environmental impact of our product packaging. Products listed above are now shipped in re-engineered packaging that minimizes the weight and the use of non-recyclable materials.b As we move through our product line, we will indicate re-engineered packages with our Smart Pack logo.

  • Travel-based emissions reduction calculations are estimated based on the total weight reduction of packaging materials used for all of 2013’s product sales, traveling 1,000 miles on an airplane, to provide general understanding of the impact of packaging material reduction. Calculations were made using the EPA’s shipping emissions values for different modes of transport.
  • Some Smart Pack products may show a negative weight reduction percentage as the substitution of greener packaging materials, such as the Greenwrap, at times slightly increases the weight of the product packaging.

Posted Comments:
Todd Harris  (posted 2024-04-19 10:48:59.5)
Please provide a torque specification for torqueing down the four (4) #2-56 screws that secure the 14-pin butterfly package to the heat sink.
Shiva Vikram B  (posted 2023-08-09 09:58:19.7)
We want to purchase the modulator bias tee adapter pcb separately.
ksosnowski  (posted 2023-08-18 04:17:05.0)
Hello Shiva, thanks for reaching out to Thorlabs. Yes we can offer the bias tee adapter PCB component separately as a special quote in case it's been lost or damaged. In these cases we would recommend you to contact techsupport@thorlabs.com directly, and I've reached out to discuss your application further detail.
user  (posted 2023-05-18 17:18:29.64)
Hello! We want to use LM14S2 mount with LDC8005 and TED8020, but we find that the pin configurations of LM14S2 and LDC8005 are different, the pin3 of LM14S2 is Laser Diode Anode and pin3 of LDC8005 is Laser Diode Ground, while the pin8 of LM14S2 is Not Used and the pin8 of LDC8005 is Laser Diode Anode. Do I need to swap the connection of pin3 and pin8 of the cable when using them together?
cdolbashian  (posted 2023-05-26 12:55:51.0)
Thank you for reaching out to us with this inquiry. As the butterfly diodes are Anode grounded, the pin 3 and pin 8 have identical electrical paths. You shouldn't need to swap any connectors. I have contacted you directly to discuss this in more detail.
user  (posted 2022-04-15 10:19:25.907)
Hello! Could you please tell me if the LM14S2 is thermal vacuum compatible?
cdolbashian  (posted 2022-04-20 04:40:50.0)
Thank you for reaching out to us with this inquiry. I have reached out to you directly to discuss the specific vacuum environment in which you are intending to place this device.
Ben Griffiths  (posted 2022-02-02 10:30:38.233)
Hi, I see that the bias-t provided in the LM14S2 is spec'd to 500 MHz. Ideally I would like to drive an RF signal at several GHz, do you offer a bias-t that could handle this higher rate to fit this mount?
ksosnowski  (posted 2022-03-02 11:44:48.0)
Thanks for reaching out to Thorlabs. Unfortunately we currently do not offer any drivers or mounts that can achieve these higher speeds. In the past, we have recommended using drivers and mounts offered by AV Tech (which is not affiliated with Thorlabs in any way). An alternative option to modulate at higher frequencies is to use an external source such as a LiNbO3 EO modulator. I have reached out directly to discuss your application further.
Rebekah Olson  (posted 2021-07-09 11:35:35.067)
I'd like to see a high-powered version of this mount to go along with products like the ITC4005. Some pump diodes have much thicker pins that make them incompatible with this version.
YLohia  (posted 2021-07-09 02:54:54.0)
Hello, thank you for your feedback. I have posted your suggestions on our internal engineering forum for consideration as a future product.
Wieslaw Jasiewicz  (posted 2020-11-14 10:23:38.04)
Hi, I can not find main PCB wiring and parts (U1) specification within LM14S2 documents.Would it be possible to get it as it is necessary for our application? Regards Wieslaw
asundararaj  (posted 2020-11-17 08:24:02.0)
Thank you for contacting Thorlabs. The PCB design and circuitry are considered proprietary and typically, we are not able to share this. I will reach out to you directly regarding your application.
Ashwin Vijayasai  (posted 2020-02-27 04:55:08.153)
Do you have a Butterfly Laser Diode Mount version where external case temperature can be controlled. Newport has one item that can control external case temp. from -5C to 85C. LDM-4984T https://www.newport.com/f/telecom-laser-diode-mounts
asundararaj  (posted 2020-02-27 04:12:04.0)
Thank you for your feedback. At the moment, we do not have a butterfly laser diode mount with external case temperature control. I have added this idea to our internal product forum for discussion to offer this at a future time.
Matthew Majewski  (posted 2019-09-26 22:07:42.733)
Hello, I understand that the bias-T adapter supplied will only work with diodes that have the correct internal circuity, but my question is if it would be possible to use your laser diode bias-T PCB component to externally wire up a modulation input for other diode types?
asundararaj  (posted 2019-10-02 11:05:27.0)
Thank you for your Feedback. To use the Bias-T adapter with other configurations of diodes in a Butterfly package, you can manually configure the LM14S2-UA to suit the pin configurations of your diode.
HYUNJONG CHOI  (posted 2019-08-27 17:56:47.8)
Nice to meet you. I'm try to find the evaluation board of thorlabs CW laser "SFL1550P". In the manual of SFL1550P, LM14S2 will be used for mounting the laser SFL1550P. Is it mean that LM14S2 can be used for the evaluation board of SFL1550P? Please reply. Thank you Your sincerely, Choi
YLohia  (posted 2019-08-27 09:25:51.0)
Hello Choi, thank you for contacting Thorlabs. The LM14S2 is intended to serve as a proper mount for butterfly laser diodes and can be used for nominal testing of the SFL1550P. I have reached out to you directly to gather more details about your application and requirements.
bsvikram  (posted 2017-05-23 01:24:29.873)
Hi, We want to use bias-t to modulate the current of a type -1 diode (SFL 1550S). But the manual says that the bias tee is for type-2 diodes only. How can we modulate type -1 diodes at high frequencies. We also have CLD 1015, but it is also limited in modulation frequency range.
nbayconich  (posted 2017-06-09 09:33:29.0)
Thank you for contacting Thorlabs. The bias-T adapter in the LM14S2 is only compatible with Type 2 Telecom Laser Diodes. Type 2 telecom butterfly diodes are designed specifically to be modulated by a bias-T RF circuit. The type 1 butterfly diode packages do not have the proper circuitry in order to be modulated in a bias-T circuit. Some alternative options to modulate your Type butterfly diodes at higher frequencies is to use an external modulating source such as a LiNbO3 EO modulator which can modulate up to 40 Gb/s . Several of our Laser Diode current drivers can directly modulate the type 1 butterfly diode mounts through the LM14S2. For example the ITC series controllers can directly modulate from DC to 150Khz. A Techsupport representative will contact you directly with more information.
savin.saju  (posted 2017-03-07 21:59:26.173)
dear Sir , LM14S2 is used for 14 pin butterfly package. Currently, there are 10 pin butterfly package laser. Do you have laser mount for 10-pin butterfly package??? please reply
jlow  (posted 2017-03-08 09:01:37.0)
Response from Jeremy at Thorlabs: We do not currently have a 10-pin butterfly mount. I will contact you regarding a custom solution.
schdingo  (posted 2014-11-18 15:00:38.487)
Dear Sir or Madam, what is the maximum heat capacity of the LM14S2? Sincerely
jlow  (posted 2014-12-10 05:07:40.0)
Response from Jeremy at Thorlabs: We do not have a spec on the maximum heat capacity but it is estimated to be around a few W. We will contact you directly to discuss more about suitability of the mount with your application.
emsia  (posted 2013-11-19 10:52:41.403)
Dear Sir/Madam, I am using ILX LDC to control my laser mounted on LM14S2. Everything works perfectly except when the laser is on, the LED does not turn on. The intelock is on bypass mode. The pin 1 os LD is connected to intrlk of the ILX LDC and pin 5 to the ground. any suggestions would be appreciated. Thank you
jlow  (posted 2013-11-19 09:23:30.0)
Response from Jeremy at Thorlabs: The LED indicator needs a certain amount of current (5-10mA) to turn on. We will get in touch with you directly to troubleshoot this.
thomas.chassagne  (posted 2013-07-02 15:29:14.367)
Hi, I would like to use the LM14S2 with the TED200 TEC controller and an external electronic board that command the bias current. In order to disable the Status and the Interlock function, Should I switch the TEC Lock button to "Bypass" ? In the Operating Manual, it's said that a resistor should be used to limit the curent into the PIN1 to between 5. Thus, if I connect the "driver" side of the resistor to 5V, I should use a 500Ohm resistor and connect the PIN5 to the ground ? Thanks, Thomas
tcohen  (posted 2013-07-11 16:20:00.0)
Response from Tim at Thorlabs to Thomas: Thank you for contacting us. Yes, it should be switched to Bypass. You can use that resistance but you may use slightly higher as the current should be limited to a maximum of 10mA.
mlaroton  (posted 2013-03-14 10:48:56.47)
Hi, I would like to use the LM14S2 mount with the FLD5F10NP-A Modulator-integrated DFB laser. In this laser, the case ground is the laser cathode. I wonder if I can still use your mount; do I need a non-standard Adapter Card? or does this feature prevents me to use your mount at all? Thanks, Miguel.
tcohen  (posted 2013-03-14 13:22:00.0)
Response from Tim at Thorlabs: Physically it appears as if your modulation connection opposite to the pins would interfere with our package designed for a 14pin butterfly. Even if this were to fit however, and a custom configuration card LM14S2-UA was to be used, the LM14S2 is suitable only for anode-grounded diodes.
jjurado  (posted 2011-06-15 11:29:00.0)
Response from Javier at Thorlabs to zhemin.cai: Thank you very much for contacting us. We can certainly provide reference drawings that you might be able to use in order to determine whether the LM14S2 will work with your pigtail. Please contact us at techsupport@thorlabs.com, and we will gladly assist you.
zhemin.cai  (posted 2011-06-10 06:55:59.0)
Dear Sir/Madam, I am wondering is that possible to get the mechanical drawing for the LM14S2? Becasue we want to use it to hold a long butterfly package, I want to check if it is fit in or not. Cheers. Zhemin.Cai
tor  (posted 2011-01-04 14:35:52.0)
Response from Tor at Thorlabs to mhafiz.abakar: Thank you for your interest in our LM14S2. This mount is compatible with our LDC8040 and TED8040 via compatible connector cables, http://www.thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=895 . We recommend a CAB400 to connect to the LDC and a CAB420-15 to connect to the TED.
mhafiz.abakar  (posted 2010-12-28 21:23:58.0)
Is this laser diode mount suitable to be used with LDC8040 and TED8040 on a pro800 mainframe. thanks.
apalmentieri  (posted 2010-02-10 08:58:39.0)
A response from Adam at Thorlabs to serefocal: The LM14S2 is designed to be used with a temperature controller, like the TED200C. It has the ability of controlling the temperature between 0 and 70 degrees C. The temperature coefficient of the heat sink is 3 degreeC/W. I will email you directly to answer any other questions you may have.
serefocal  (posted 2010-02-10 10:03:30.0)
Dear Sir/Madam:What is the "LM14S2 Butterfly Laser Diode Mounts"s Heat Dissipation Capacity? May I learn? Thanks...
klee  (posted 2009-09-09 10:44:30.0)
A response from Ken at Thorlabs to yuhengc: An applications engineer will contact you directly to discuss about the problem.
yuhengc  (posted 2009-09-09 09:24:44.0)
Dear Sir/Madam: We are using LM14S2. Recently we found the current waveform of DFB LD was not stable. The current drive seems to be OK. Since it is new one and I tested with two simulated diode in series. There was no problem. But when I connected to the LD. The current waveform ( monitored from the current feedback)was not constant. Even worst, after a period of fluctuation, it kept decreasing and finally went down to zero. Sometime, if I switched off the driver and powered up again. The current recovered. The LD is the NEL with a little difference layout of pin to type two laser. I am using type 2 configuration card with pin12 connected as the instruction from the manual. What ,do you think, is the reason?
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14-Pin Butterfly Laser Diode Mounts

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
LM14S2 Support Documentation
LM14S2Universal 14-Pin Butterfly Laser Diode Mount
LM14S2-UA Support Documentation
LM14S2-UACustomer Inspired! User-Configurable Pin-Out Card for LM14S2