Shinichi Matsuoka

100-TW sub-20-fs Ti:sapphire laser system operating at a 10-Hz repetition rate

We developed a compact three-stage Ti:sapphire amplifier laser system that produced peak power in excess of 100 TW for a pulse duration of less than 19 fs and an average power of 19 W at a 10-Hz repetition rate. A final 40-mm-diameter Ti:sapphire amplifier is pumped by a Nd:YAG master-oscillator-power-amplifier system that produces ~7-J output of 532-nm radiation. The spatial beam quality is approximately 2 times diffraction limited for the full amplified compressed output pulse. With f/3 optics, this system should therefore be capable of producing a focused intensity of ~3x10(20) W/cm(2) .

Generation of 16-fs, 10-TW pulses at a 10-Hz repetition rate with efficient Ti:sapphire amplifiers.

We describe a two-stage Ti:sapphire amplifier laser system that is capable of producing 16-fs pulses of 10-TW peak power at a 10-Hz repetition rate. Thin solid etalons were used to control gain narrowing and gain saturation during amplification. A cylindrical mirror expander was used to permit compensation of the dispersion of the system. An efficiency greater than 90% of the theoretical maximum for conversion of 532-nm pump light to 790-nm radiation is demonstrated.

Wave-front measurements of terawatt-class ultrashort laser pulses by the Fresnel phase-retrieval method

We demonstrate single-shot wave-front measurements of high-peak-power 100-fs laser pulses using the Fresnel phase-retrieval method. The wave fronts are reconstructed from only two intensity distributions at two planes along the optical axis and are measured by means of simple charge-coupled-device cameras. Wave fronts of a terawatt-class laser pulse are measured to be better than 0.36λ, peak to valley, when compared with the measured far-field intensity distributions of the beam.

High efficiency second-harmonic generation in four-pass quadrature frequency conversion scheme

Abstract A four-pass quadrature frequency conversion scheme was developed to generate green output with high efficiency for pumping an ultrashort pulse laser system. With this scheme, an efficiency from fundamental energy into total second harmonic energy in excess of 80% was achieved for frequency doubling of 1064 nm in KTP with a low input fundamental laser intensity of 76 MW/cm 2 . A total second-harmonic output of 486 mJ was obtained with 607 mJ of the input 1064-nm fundamental laser at 10 Hz.

Highly efficient second harmonic generation by using four pass quadrature frequency conversion

A novel frequency converter architecture of four-pass quadrature frequency conversion scheme was developed aiming to achieve high conversion efficiency. A high conversion efficiency of more than 80% has been achieved in this scheme for frequency doubling of 1064-nm in KTP with a low input fundamental laser intensity of 76 MW/cm2. A second- harmonic output of 486 mJ was obtained with 607 mJ of the input 1064-nm fundamental laser at 10 Hz.

Highly efficient second-harmonic generation in novel four-pass quadrature frequency conversion

Abstract A four-pass quadrature frequency conversion scheme was developed for achieving high conversion efficiency. With this scheme, an efficiency in excess of 80% was achieved for frequency doubling of 1064 nm in KTP with a low input fundamental laser intensity of 76 MW / cm 2 . A second-harmonic output of 486 mJ was obtained with 607 mJ of the input 1064 nm fundamental laser at 10 Hz.

High-efficiency second harmonic generation in four-pass quadrature frequency conversion scheme

A four-pass quadrature frequency conversion scheme was developed to generate green output with high efficiency for pumping an ultrashort pulse laser system. With this scheme, a efficiency from fundamental energy into total second harmonic energy in excess of 80% was achieved for frequency doubling of 1064-nm in KTP with a low input fundamental laser intensity of 76 MW/cm2. A total second-harmonic output of 486 mJ was obtained with 607 mJ of the input 1064- nm fundamental laser at 10 Hz.

Development of a high-peak and high-average power Ti:sapphire laser system

We have developed a two-stage Ti:sapphire amplifier system, which is capable of producing 16 fs, 10 TW pulses at a 10 Hz repetition rate. We also describe an extension of this system to a peak power of 100 TW and an average power of 20 W level.

Generation of 100 TW, Sub-20 fs Pulses at a 10 Hz Repetition Rate in Ti:Sapphire

We have developed a compact three-stage Ti:sapphire amplifier laser system that produces a peak power in excess of 100 TW for a pulse duration of less than 19 fs and an average power of 19 W at 10 Hz repetition rate. The spatial beam quality is about twice the diffraction limited for the full amplified, compressed output pulse.