Abstract: A system is provided that includes a light-emitting diode (LED); a temperature sensor in thermal contact with the LED and capable of measuring an operating temperature and generating an operating temperature signal; and a temperature regulating system capable of receiving the operating temperature signal and regulating the operating temperature based on the operating temperature signal. A method for stabilizing the temperature of an LED is provided. A method is provided that includes providing a system comprising an LED, a reaction region, and a sample in the reaction region; generating excitation beams with the LED; directing excitation beams to the sample; detecting an optical property of the sample to obtain detection data; measuring the- operating temperature of the light emitting diode; and adjusting the detection data of an excitation beam characteristic shift related to the operating temperature, when the LED is operated at the operating temperature to generate the excitation beams.