Effect of thermistor on wavelength variation of superluminescent diode over the whole operating temperature range

A unilateral 6-pin butterfly packaging superluminescent diode module was fabricated, and the mean wavelength variation was measured under different ambient temperatures, i.e. 298.15K, 228.15K and 343.15K. Under 228.15K, the mean wavelength is longer than that under 298.15K, and under 343.15K, the mean wavelength is shorter than that under 298.15K. Simulation result shows that the resistance distribution of thermistor is easily affected by ambient temperature which is due to a low thermal conductivity, even though there is a thermoelectric cooler which controls the operating temperature of superluminescent diode chip. To ensure that the thermistor resistance value is 10K Omega, the thermoelectric cooler has to heat at 228.15K and cool at 343.15K. A method of reducing the thickness of thermistor to decreasing the maximum temperature difference in whole operating temperature range is proposed, which is necessary for decreasing the wavelength variation of superluminescent diode module.