Study Of Novel Ytterbium-doped Ultrashort Laser System

Ever since the beginning of the 1990s, titanium sapphire has become the crystal choice for ultrashort laser generation. Very short and powerful pulses, two of the most attractive aspects of ultrashort laser has stimulated high scientific research passion among people over the past few decades. Along with promising applications in the area of science, industry and iatrology, new demands of directly other wavelength ranges and cw or pulsed green laser to pump the titanium sapphire crystal have arised, which leads to the revolution of solid state laser crystals. New crystals doped with ytterbium ions, especially Yb3+-doped oxyorthosilicate crystals has been noticed rapidly as a standard 1μm region ultrashort laser generation material, with merits of high thermal conductivity, large tenability and very efficient directly pump by a high-power semiconductor laser, etc.This manuscript demonstrated efficient and reliable cw tunable lasers and cw passively mode-locked lasers based on Yb-doped crystals under direct pumping with high-power commercial InGaAs diodes. With further amplification by Yb-doped double-clad fiber amplifier, high average power of anterior lasers could attained. Main experimental discussion in each chapter are outlining as follow:1,Briefly introduction was made for the development and applications of ultrashort lasers in Chapter One. Means of solid state ultrashort laser generation with Yb-doped laser crystals was particularly discussed on the advantages.2,In Chapter Two, we have five Yb3+-doped oxyorthosilicate crystals presented. After studied their spectroscopic properties and thermo-optical properties, we introduced Yb-doped double-clad fiber by its structure and end-design.3,Continuous-wave lasers were realized by there laser cavity:plane to plane, three mirror V-shaped and five mirror Z-shaped, for Yb:YSO, Yb:LSO, Yb:LYSO, Yb:GYSO and Yb:GSO oxyorthosilicate crystals. Plane to plane Yb:GYSO laser were performed under the slope efficiency of 107.9% corresponding to an optical-to-optical conversion efficiency of 84%, especially.4,In Chapter Four, a SF14 prism was employed as tuning element in three mirror V-shaped resonance. By means of the laser cavity, four quasi-continuous and smooth tuning lasers all with a range over 100 nm were achieved by Yb:YSO, Yb:LSO, Yb:LYSO and Yb:GYSO laser crystals. The boardest turning range of 114 nm was achieved for Yb:LSO laser, and the highest power 4.4 W at 1084.9 nm was obtained by Yb:LYSO oscillator. 5,In five mirror V-shaped oscillator, SESAM was introduced as the passively mode-locked element. Continuous-wave ns mode-locked lasers were attained for Yb:YSO and Yb:LYSO crystals. With further experimental study, second harmonic mode-locked laser for Yb:YSO oscillator could be realized. Under 50 W pumping source, laser pulse with 145.9 ps autocorrelation trace at 1033.7 nm have been achieved by Yb:LYSO crystal.6,High-power laser radiation could be obtained from Yb-doped fiber amplifiers. In Chapter Six, we attained 30-W amplified lasers for both wavelength 1053 nm and 1083 nm of Yb:YSO, Yb:LSO and Yb:LYSO cw laser. After the first round amplifier, about 10-W output laser at about 1058 nm with an optical-to-optical conversion efficiency of 37% were obtained for Yb:YSO and Yb:LYSO cw mode-locked laser.7,At last, we organized an summary for the manuscript with further research pivots attached...