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Application Notes

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  A Thermoelectric Cooler Temperature Controller for Fiber Optic Lasers: Climatic Pampering for Temperamental Lasers &mdash AN89
  PDF, 1.6 Mb, File published: Apr 1, 2001
  This application note presents circuitry for maintaining 0.01°C temperature control of fiber optic lasers over wide ambient range variations. The circuitry also features high efficiency power delivery, compact size and low noise. Detailed descriptions of circuitry and results are given with special emphasis on thermal loop optimization. An appended section covers practical considerations for thermoelectric cooler-based control loops.
  Extract from the document

  Application Note 89
  April 2001
  A Thermoelectric Cooler Temperature Controller
  for Fiber Optic Lasers
  Climatic Pampering for Temperamental Lasers
  Jim Williams
  INTRODUCTION
  Continued demands for increased bandwidth have resulted in deployment of fiber optic-based networks. The
  fiber optic lines, driven by solid state lasers, are capable of
  very high information density. Highly packed data schemes
  such as DWDM (dense wavelength division multiplexing)
  utilize multiple lasers driving a fiber to obtain large multichannel data streams. The narrow channel spacing relies
  on laser wavelength being controlled within 0.1nm (nanometer). Lasers are capable of this but temperature
  variation influences operation. Figure 1 shows that laser
  output peaks sharply vs wavelength, implying that laser
  wavelength must be controlled well within 0.1nm to maintain performance. Figure 2 plots typical laser wavelength
  vs temperature. The 0.1nm/В°C slope means that although
  temperature facilitates tuning laser wavelength, it must
  not vary once the laser has been peaked. Typically, temperature control of 0.1В°C is required to maintain laser
  operation well within 0.1nm. Temperature Controller Requirements
  The temperature controller must meet some unusual
  requirements. Most notably, because of ambient temperature variation and laser operation uncertainties, the controller must be capable of either sourcing or removing heat
  to maintain control. Peltier-based thermoelectric coolers …

Articles

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  A Thermoelectric Cooler Temperature Controller for Fiber Optic Lasers &mdash LT Journal
  PDF, 472 Kb, File published: Sep 1, 2001
  Extract from the document

  DESIGN FEATURES A Thermoelectric Cooler Temperature
  Controller for Fiber Optic Lasers
  by Jim Williams
  Introduction Temperature Controller
  Requirements
  The temperature controller must meet
  some unusual requirements.1 Most
  notably, because of ambient temperature variation and laser operation
  uncertainties, the controller must be
  capable of either sourcing or removing
  heat to maintain control. Peltier-based
  thermoelectric coolers (TEC) permit
  this but the controller must be truly
  bidirectional. Its heat flow control
  must not have dead zone or untoward
  dynamics in the “hot-to-cold”
  transition region. Additionally, the
  temperature controller must be a precision device capable of maintaining
  control well inside 0.1В°C over time
  and temperature variations.
  Laser based systems packaging is
  compact, necessitating small solution size with efficient operation to
  avoid excessive heat dissipation. …

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Manufacturer's Classification

• Monitor, Control and Protection > Thermoelectric Cooler Controller