The Development Of Novel Solid State Laser And The Generation Of Supercontinuum Spectrum

Diode-pumped solid state laser?DPSSL?as immediate hot area of laser research focus have important significance and wide application because of their unique advantages such as high efficiency,low consumption,compact structure.This dissertation is aimed to develop novel diode-pumped solid state laser that strive for shorter pulse width,higher energy and more convenient and stable to use and be able to apply for generating octave-spanning supercontinuum spectrum.Moreover,the thesis also introduces the situation of development with respect to diode-pumped solid state laser and the generation of supercontinuum.Recently,supercontinuum spectrum generated by ultra-short pulse is an important branch of nonlinear optics.The continuous progress of supercontinuum theory and technology improve the development of optical metrology,optical spectroscopy,modern biology and medicine,high speed optical communication etc.There are two main methods to generate supercontinuum spectrum at present.One is by means of micro structure fiber?Photonic crystal fiber?,another is using tapered fiber.Tapered fiber is a new type of processing technology for fiber.The fiber was by means of heating and stretching in a flame which would result in changing from shape and property of fiber.It will creat richer application in terms of normal fiber or photonic crystal fiber.The main results and innovations are summarized as follows:1.Successfully created femtosecond?fs?solid state laser which use multiple Yb³⁺ doped crystal as gain material.Among of these crystal,Yb:YGG is not only a potential material which has similar thermal mechanical nature to Yb:YAG,it enjoys the added advantage of four times wider emission spectrum,reaching at 22 nm.This crystal theoretically can sustain approximately sub-100 fs.In this experiment,Yb:YGG solid state laser with passively modelocked technology finally generate 196 fs,300 m W pulse.Moreover,the other Yb³⁺ doped crystals also have been used to build solid state lasers as gain material,such as Yb:LYSO,Yb:YCOB,Yb:CYA.2.I have obtained the supercontinuum spectrum from Yb:YCOB laser,ranging from 550 nm to 1350 nm.Firstly,building a tapered fiber instrument based on technology of tapered fiber.Then processed common fiber to tapered fiber and guided the laser pulse into tapered fiber to broaden the spectrum.Based on the result of experiment I discussed the prospect that apply the supercontinuum spectrum for new type optical frequency comb.