Browsing by Author "Chen, Wei-Jan"

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Carrier-Envelope-Phase Control of Ultrashort Periodic Pulses Synthesized from Raman Generated Combs
(2009-01-01)
Hsieh, Zhi-Ming
;
Lai, Chien-Jen
;
Chan, Han-Sung
;
Wu, Sih-Ying
;
Lee, Chao-Kuei
The carrier-envelope phase of Raman generated ultrashort pulses is controlled by driving the Raman coherence with a beam at near the raman resonance frequency and its second harmonic.
Controlling the Carrier-Envelope Phase of Raman-Generated Periodic Waveforms
(2009-05-29)
Hsieh, Zhi-Ming
;
Lai, Chien-Jen
;
Chan, Han-Sung
;
Wu, Sih-Ying
;
Lee, Chao-Kuei
We demonstrate control of the carrier-envelope phase of ultrashort periodic waveforms that are synthesized from a Raman-generated optical frequency comb. We generated the comb by adiabatically driving a molecular vibrational coherence with a beam at a fundamental frequency plus its second harmonic. Heterodyne measurements show that full interpulse phase locking of the comb components is realized. The results set the stage for the synthesis of periodic arbitrary waveforms in the femtosecond and subfemtosecond regimes with full control.
Controlling the Light Waveform of Attosecond Pulse Train by Synthesized Multi-colored Laser Fields
(2012)
Chen, Wei-Jan
;
Wang, Hong-Zhe
;
Lin, Ruei-Yin
;
Lee, Chao-Kuei
;
Pan, Ci-Ling
We show a process to generate a high peak power and waveform controllable light source. The bandwidth is more than two octaves, so the electric field oscillation in the pulse envelope is close to half cycle. It is promising to apply to high-order harmonic generation by sub-cycle pulse.
Full Control of the Carrier-Envelope Phase of Raman-Generated Single-Cycle Waveforms
(2009-01-01)
Hsieh, Zhi-Ming
;
Lai, Chien-Jen
;
Chan, Han-Sung
;
Wu, Sih-Ying
;
Lee, Chao-Kuei
Precise control of the carrier-envelope phase of Raman genearated ultrashort pulses is achieved by generating a Raman frequency comb using an infrared laser pulse and its second harmonic to drive the Raman coherence. (C) 2009 Optical Society of America
Pulse Shaper Assisted Characterization of Single-cycle Optical Pulses
(2009)
Hsieh, Zhi-Ming
;
Lai, Chien-Jen
;
Liang, Wei-Hong
;
Tang, Tsung-Ta
;
Chen, Wei-Jan
Shaper-assisted autocorrelation is developed to characterize single-cycle pulses. The correlation signal show significantly improved signal-to-noise ratio and thus accuracy in pulse characterization when compared to cross-correlation obtained by splitting the spectral components of the pulse. (C) 2009 Optical Society of America
Sub-single-cycle optical pulse train with constant carrier envelope phase
(2008-04-25)
Chen, Wei-Jan
;
Hsieh, Zhi-Ming
;
Huang, ShuWei
;
Su, Hao-Yu
;
Lai, Chien-Jen
We describe the synthesis of periodic waveforms consisting of a train of pulses that are 0.83 cycles long and have an electric field pulse width of 0.44 fs using 7 Raman sidebands generated by molecular modulation in H(2). We verify by optical correlation that the carrier-envelope phase is constant in these waveforms when they are synthesized from commensurate sidebands. The estimated overall shift of the carrier-envelope phase is less than 0.18 cycles from the first to the last pulse of nearly 10(6) pulses in the pulse train.
Vibrational molecular modulation in hydrogen
(2006-12-01)
Huang, Shu Wei
;
Chen, Wei-Jan
;
Kung, A. H.
;
光電工程學系
;
Department of Photonics
Detailed numerical modeling of using the vibrational coherence of H-2 for molecular modulation is presented. The focus of the calculation is on a strongly driven system aimed at producing many sidebands in the presence of Doppler broadening and the effects of collisions at room temperature. It is shown that Dicke narrowing that reduces the Doppler width plays a critical role in high order sideband generation in room temperature H-2. In addition, the calculation shows that generation of many sidebands favors the phased state as has been reported in all gas phase experiments and is primarily a consequence of the Stark shifts that result from the applied high intensities. The influence of self-focusing in the gas medium that has been conjectured in previous studies is only secondary. The numerical results agree with experimental data obtained in our laboratory, where we have succeeded in generating collinearly propagating Raman sidebands with wavelengths that range from 2216 nm in the infrared to 133 nm in the vacuum ultraviolet. The frequencies covered by these sidebands span over four octaves for a total of more than 70 600 cm(-1) in the optical region of the spectrum.