The electrical noise evaluation of fiber-coupled LD

Abstract

ABSTRACT This paper introduces method of electrical noise evaluating of high-power fiber coupled diode laser. After photoelectricity conversion of output laser, We measure its electrical noise by analyse and test system. At the same time, we find out primary noise source through analysing 1/f noise, G-R noise and burst noise in the device systematically. Moreover we raise feasible advice on how to improve arts level and reliability of system after analysing relationship between noise and correlative arts. Experimental result shows that this method is effective and practicable . Key words: fiber coupled diode laser electrical noise reliability 1 INTRODUCTION The noise of fiber coupled LD noise consists of shot noise, hot noise and low frequency noise, which including 1/f noise and generate-recombination noise (g-r noise). The noise of fiber coupled LD is not only the important factor to determine the quality of illumination system and signal noise ratio of r eceive system, but also evaluate the reliability and quality of device according to type and size of low frequency noise. It has been reported that 1/f noise was used to research the semiconductor laser. The paper introduces the study on the probable relationship between electrical noise and main parameters or productive craft of the device, and give the analyzing about the relationship between electrical noise spectrum density and working reliability of fiber coupled LD, by measuring its low frequency electrical noise spectrum and its type. Moreover, it is helpful to understand deeply the form mechanism of output noise of the fiber coupled LD. At the same time, we measure its the electrical noise spectrum and light noise spectrum before aging and after it separately. The electrical noise spectrum density reflects dynamic current change which in the device, and we can forecast its reliability. The light noise spectrum density not only reflect the size and type of electrical noise of the fiber coupled LD, but also related with the film quality and stuff of fiber end face coating, the smooth of the fiber end processing and the quality of mechanical location. Therefore, it is probably and synthetically reflect the reliability of the fiber coupled LD by analyzing its light noise spectrum density and electrical noise spectrum density.