서지주요정보
주파수분해 광게이팅 방법을 이용한 펨토초 레이저 펄스의 시간적 특성연구 = Temporal characterization of a femtosecond laser pulse using frequency-resolved optical gating technique
서명 / 저자 주파수분해 광게이팅 방법을 이용한 펨토초 레이저 펄스의 시간적 특성연구 = Temporal characterization of a femtosecond laser pulse using frequency-resolved optical gating technique / 홍경한.
저자명 홍경한 ; Hong, Kyung-Han
발행사항 [대전 : 한국과학기술원, 1998].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8008472

소장위치/청구기호

학술문화관(문화관) 보존서고

MPH 98030

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

A single-shot frequency-resolved optical gating (FROG) was fabricated and used to characterize pulses from a femtosecond, chirped-pulse amplification Ti:Sapphire laser developed at KAIST. The self-diffraction (SD) and second harmonic generation (SHG) FROG schemes were used to obtain the FROG trace (the spectrogram of the FROG signal) from which the intensity and phase profiles of a selected pulse was reconstructed using FROG algorithm. An interferometric autocorrelator and a single-shot intensity autocorrelator were used to measure the pulses from the Ti:Sapphire oscillator and the amplified pulses at the last stage, respectively, as the primary steps for better understanding of the FROG. The laser system could be optimized in real time by monitoring FROG trace on a charged-coupled device (CCD). The measured pulse duration, when the laser condition that produces the shortest pulse was achieved, was 29 fs, giving 2 TW output power with energy of 60 mJ. The quantative parameters regarding the phase, such as quadratic chirping parameter and group delay dispersion (GDD), were measured by polynomially fitting the phase of reconstructed field from the SD FROG trace. The GDD per unit length of a fused silica block measured by FROG was consistent to the value calculated with the optical parameters of the fused silica. The measured GDD when the pulse was not sufficiently compressed was, also, consistent with the expected GDD of the compressor composed of two gratings. This operations show that the FROG is a powerful diagnostics to analyze the phase information of ultrashort pulses. Self-consistency check was done using the concept of FROG marginal to find any possible systematic error. The inconsistency, however, was observed between calculated FROG marginal and measured one, which resulted in the inconsistency between measured pulse spectrum and retrieved one. The re-calibration of FROG trace was possible by comparing the calculated FROG marginal with measured one even if some systematic errors existed in the present FROG setup. The phase-mismatch in the nonlinear medium generated by broad-band spectrum seems to be one of the reasons for systematic errors in both FROG's, and it was found that the spectral responsivity of the CCD distorted the phase information of SHG FROG significantly. Additional experiments are in preparation to overcome these errors and to improve this FROG setup.

서지기타정보

서지기타정보
청구기호 {MPH 98030
형태사항 70 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Kyung-Han Hong
지도교수의 한글표기 : 남창희
지도교수의 영문표기 : Chang-Hee Nam
학위논문 학위논문(석사) - 한국과학기술원 : 물리학과,
서지주기 참고문헌 : p. 66-70
주제 주파수분해 광게이팅
자체상관계
극초단 펄스
펄스진단
자체에돌이
티타늄 사파이어 레이저
FROG
Autocorrelation
Ultrashort pulse
Pulse diagnostics
Self-diffraction
Ti:Sapphire laser
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