光脈衝整形器應用於兆赫輻射波形整合之研究

Abstract

本論文主要是研究光脈衝整合器及其在兆赫輻射波 型整合和飽和布拉格反射鏡特性之應用,在光脈衝整合 器上，我們用Gerchberg-Saxton 演算法，來設計飛秒脈 衝波形。 然後使用Freezing 演算法來達成最短脈衝 (transform-limited pulse)。使用此兩種演算法來達到 脈衝整合的目的，然後利用整合出的脈衝波形來合成兆 赫輻射波型，用以探測兆赫輻射的基本特性。

In this thesis, it can be demonstrated that how to design and the optical synthesis technique for a desired ultrafast optical pulse with Gerchberg-Saxton (GS) algorithm. Based on the algorithm, multi-pulse with different pulse duration, two pulses with dissimilar pulse duration and single pulses with different pulse width achieved by unalike phase pattern can be accomplished. We use a new freezing phase algorithm for complete-field attributes of femtosecond ultrashort pulse with a phase-only pulse shaping apparatus. The operational principle is based on the fact that the highest peak intensity corresponds to a complete frozen-phase state of all spectral components. Femtosecond laser pulse is achieved to be the transform-limited femtosecond laser pulse by this algorithm. Pulse shaping technology has already demonstrated a strong impact as an experimental tool providing convenient control over ultrafast laser waveforms especially for THz waveform synthesis. We illustrate this technique using several experimental examples, including manipulation of the bandwidth and the pulse number of ultrafast terahertz waveforms as well as generation of different terahertz spectrum