Constant temperature control of the SLED underlying an adjustable driving-current

A variable constant-current driver was proposed for a super luminescent diode (SLED) to meet the constanttemperature working requirement.This method was carried out by a microcomputer, MSP430, combining with proportional-integraldifferential(PID) algorithm and a semiconductor cooler.Driven by this controller,the SLED generated a stable output power and central wavelength.Experimental results demonstrated that the temperature accuracy of 0.1℃ was achieved when the environmental temperature changed from 10℃ to 40℃.The constant-driving current was stabilized at 0.1mA in the range from 0mA to 200mA.Thus,the driver can meet the demand of SLED application.