Convenient exciton lifetime measurement of quantum dots with high resolution

We develop a new kind of pump and probe based technique for exciton lifetime measurement in quantum dots. The resolution of this method is of femtosecond order, which is decided by the width of the pump and probe pulses. Using this method, we measure the lifetime on a quantum dots ensemble sample, and investigate the conditions to ensure this technique's validity. With proper settings of the pump and probe pulses, it is an effective way for this kind of lifetime measurement combining high resolution and outstanding convenience which seem to be incompatible in conventional methods.