Fiber-optics based micro-photoluminescence system

摘要

Spatially resolved photoluminescence (PL) apparatus is used for the non-destructive characterization of a semiconductor sample. PL excitation from a diode laser is transmitted through a dichroic coupler and, in turn, over a fiber to a fiber collimator wherein the laser light is collimated into a pump beam prior to entering an air path. The air path is composed primarily of an objective lens. The objective lens focuses the pump beam on the sample surface. The photoluminescence signal emitted by the sample travels the same path but in the opposite direction as the pump beam and is collected by the same fiber as a reflected signal. The dichroic fiber coupler is used to separate the return signal from the pump beam with a low insertion loss for each beam. The return PL signal is fed to an optical spectrum analyzer using a single mode fiber connected to the coupler. The sample is placed on a rotational stage capable of x, y and z movement under computer control.