ASPIC's are very sensitive to temperature changes. Already variations in the order of miliKelvin can have dramatic influence in the performance of the device.
These temperature variations have different origins and need to be dealt with in different ways. First source is of course the surrounding atmosphere, including near heat sources (ie, electronics and power sources), but also on chip devices can be the cause. More and more ASPIC's have active, thus heat generating, components like modulators and light sources, (SOA's).
With the TEC and Thermistor which can be supplied and integrated in our packages, your ASPIC can function at various external temperatures. With a simple control loop the effects of slow and fast variations in the surrounding temperature can be reduced. This typically enables an operation window of about 70 degrees C at stability of about 1 miliKelvin.
Using FEM models of the package thermal behavior the package/housing we can assist in optimizing the location of the thermistor(s). With some additional effort like increased stabilization of the TEC power source, the thermal stability of the packaged system can be improved towards a few microKelvin.
For increased functionality and use more and more active components become available for ASPIC's. Adding detectors, modulators light sources and is becoming more and more state of the art and even opto-electronics integration is maturing fast. Drawback is that these components all generate heat, and more important, the heat dissipation varies over time (operating components at different current or even switching them on and off.
The local temperature variations will have their (potentially dramatic) effect on the optical behavior of the ASPIC. Early in the ASPIC design phase, the position of all these heat sources in comparison to (most) temperature sensitive components can still be optimized. Using simulations the short and longer term temperature effects as a function the position of various components on (and near) the ASPIC can be studied and optimized.
It might be that re-optimization of the package/housing is required after optimizing the local thermal behavior. As example the thermistor might need replacing. Also the use of a second thermistor might be considered, for instance to have different control strategies as function of the operation mode of the ASPIC or complete device.