Thermoelectric Cooling Solutions

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Superluminescent Diodes

Superluminescent diodes (SLDs) are similar to semiconductor lasers by mechanism of light emitting. However, unlike lasers SLD does not have a mirror cavity. Due to this SLDs possess a unique combination of properties: on the one hand they have a power output and brightness similar to semiconductor lasers; on the other hand, the broad linewidth radiation similar to conventional LEDs.

Broad band of radiation means a low coherence length that provides a micrometric resolution in optical coherence tomography (OCT) and a high sensitivity in a fiber-optic gyroscopes. Superluminescent diodes are also used to test optical elements.

Requirements to the heat rejection and thermal stabilization in SLD are similar, with the same requirements for semiconductor lasers, as the main element is a light-emitting semiconductor chip generating heat. SLD operation performance and long-term reliability depend on temperature conditions – dissipation of heat and thermal stabilization.

Single-stage thermoelectric Peltier coolers (TECs) are typically used for thermal management in SLDs. Deep cooling is not required in general, needs small cooling power, but enough space for laser chip and its arrangement for mounting onto cooler cold side.

TECs are the optimal and the only solution for SLDs in terms of efficiency and long operation life.

TEC has unique reliability of several hundred thousand hours of continuous operation. It means more than 20-25 years of operation without maintenance and replacement, which is important for telecommunication systems.

All the products are manufactured in whole conformity with the standard of reliability Telcordia GR468 Core. The modules of RMT are fully compliant with RoHS и REACH requirements.

Depending on the SLD package design the company RMT offers a wide variety of standard sizes of thermoelectric modules for such applications.


Butterfly package is very common for SLDs applications.

For the Butterfly style company RMT produces several special series of single-stage TECs. The feature of such thermoelectric modules is an elongated shape, comfortable for the most useful location of TEC in boxed Butterfly package and mounting of laser chip with optical and electronic elements on the TEC cold side.

  • Series 1ML06 and 1ML07 contain a set of standard sizes of miniature TECs suitable for Butterfly type package. These TECs are very common for Butterfly form factor and become de-facto standard during recent years.
  • RMT Series 1MDL06 miniature modules with up to 100% higher cooling capacity. Higher cooling capacity gives additional reserve in terms of temperature regulation from ambient, or in certain cases – reduces thermoelectric cooler electrical power consumption.

In addition, RMT offers the sub-assembly solutions – thermoelectric coolers mounted in standard Butterfy housing.


The use of TO packages, for example, type TO8, TO66, etc is also common. .

For such SLDs company RMT offers a large set of standard TECs of single-stage series 1MC04 and 1MC06. For more powered SLDs or miniature design with high power density, the series of modules with higher cooling capacity are suitable - single-stage series 1MD04 and 1MD06.

In addition, RMT offers complete solutions – thermoelectric cooling modules mounted in standard or customized TO-style packages.

To select a suitable solution and the optimal TEC for an application, the supporting Online TEC Assistance is available at RMT’s website. For detailed modeling and calculations the company RMT provides our customers by free software TECCad or iTECPad.

Or contact RMT for immediate advice and assistance.