Recently, α-Al2O3：C crystal with highly sensitive thermoluminescence （TL） and optically stimulated luminescence （OSL） has been successfully grown by the temperature gradient technique. This paper investigates th...Recently, α-Al2O3：C crystal with highly sensitive thermoluminescence （TL） and optically stimulated luminescence （OSL） has been successfully grown by the temperature gradient technique. This paper investigates the heating rate dependence of TL sensitivity, light-induced fading of TL signals and thermal stability of OSL of α-Al2O3：C crystals. As the heating rate increases, the integral TL response decreases and the dosimetric glow peak shifts to higher temperatures in α-Al2O3：C crystals. Light-induced fading of TL increases with the irradiation dose, and TL response decreases as the exposure time increases, especially in the first 15 minutes. With the increasing intensity of the exposure light, the TL fading of α-Al2O3：C crystal increases sharply. The OSL response of as-grown α-Al2O3：C crystal is quite stable below 373 K and decreases sharply for higher temperatures.展开更多
A new type of optical parametric chirped pulse amplifier is designed and analyzed for the amplification of pulse centered at 808 nm. A novel crystal, yttrium calcium oxyborate YCa40（BO3）3 （YCOB）, is utilized in th...A new type of optical parametric chirped pulse amplifier is designed and analyzed for the amplification of pulse centered at 808 nm. A novel crystal, yttrium calcium oxyborate YCa40（BO3）3 （YCOB）, is utilized in the power amplification stage of optical parametric amplification （OPA）. Noncollinear phase matching parameters in the xoz principle plane of YCOB, compared with those in BBO and DKDP, are analyzed by numerical simulation. The results show that YCOB rather than DKDP can be used in the power amplification stage of OPA to realize the amplification of chirped pulse to several joules with a gain bandwidth exceeding 100 nm. This can be used to gain a high intensity pulse of -10 fs after the compressor.展开更多
A numerical model of optical parametric amplification （OPA） is introduced to investigate the impact of wavefront phase distortion of pump on the beam quality of signal. Numerical results show that the unidentical wa...A numerical model of optical parametric amplification （OPA） is introduced to investigate the impact of wavefront phase distortion of pump on the beam quality of signal. Numerical results show that the unidentical walk-off directions of the pump and the idler waves are the main factors leading to the transfer of wavefront phase distortions of the pump to the signal, and by reducing the angle between the two directions, the beam quality factor （M2） can be greatly decreased and hence the good beam quality of the signal can be maintained.展开更多
We study and experimentally demonstrate a sensitive single-shot correlation system in which only a diffraction grating is used to produce a transverse time delay （TTD） in the reference pulse.The mechanism of the TTD...We study and experimentally demonstrate a sensitive single-shot correlation system in which only a diffraction grating is used to produce a transverse time delay （TTD） in the reference pulse.The mechanism of the TTD introduced by the grating and the formation of the relative time delay （RTD） in the noncollinear correlation system are analyzed in detail.By using our system,we successfully measured the temporal duration of picosecond laser pulses,and a time resolution of ～0.047 ps is obtained at 1047 nm.The impact of the grating dispersion and the second harmonic beam walk-off effect on the measurement are considered.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60607015 and 60878041)the Innovation Funds from Shanghai Institute of Ceramics,CAS
文摘Recently, α-Al2O3：C crystal with highly sensitive thermoluminescence （TL） and optically stimulated luminescence （OSL） has been successfully grown by the temperature gradient technique. This paper investigates the heating rate dependence of TL sensitivity, light-induced fading of TL signals and thermal stability of OSL of α-Al2O3：C crystals. As the heating rate increases, the integral TL response decreases and the dosimetric glow peak shifts to higher temperatures in α-Al2O3：C crystals. Light-induced fading of TL increases with the irradiation dose, and TL response decreases as the exposure time increases, especially in the first 15 minutes. With the increasing intensity of the exposure light, the TL fading of α-Al2O3：C crystal increases sharply. The OSL response of as-grown α-Al2O3：C crystal is quite stable below 373 K and decreases sharply for higher temperatures.
基金supported by the National "863" Program of China under Grant No. 2009AA8044010
文摘A new type of optical parametric chirped pulse amplifier is designed and analyzed for the amplification of pulse centered at 808 nm. A novel crystal, yttrium calcium oxyborate YCa40（BO3）3 （YCOB）, is utilized in the power amplification stage of optical parametric amplification （OPA）. Noncollinear phase matching parameters in the xoz principle plane of YCOB, compared with those in BBO and DKDP, are analyzed by numerical simulation. The results show that YCOB rather than DKDP can be used in the power amplification stage of OPA to realize the amplification of chirped pulse to several joules with a gain bandwidth exceeding 100 nm. This can be used to gain a high intensity pulse of -10 fs after the compressor.
基金supported by the National"863"Program of China under Grant No.2007AA804801.
文摘A numerical model of optical parametric amplification （OPA） is introduced to investigate the impact of wavefront phase distortion of pump on the beam quality of signal. Numerical results show that the unidentical walk-off directions of the pump and the idler waves are the main factors leading to the transfer of wavefront phase distortions of the pump to the signal, and by reducing the angle between the two directions, the beam quality factor （M2） can be greatly decreased and hence the good beam quality of the signal can be maintained.
基金supported by the National "863" Program of China under Grant No. 2009AA8044010
文摘We study and experimentally demonstrate a sensitive single-shot correlation system in which only a diffraction grating is used to produce a transverse time delay （TTD） in the reference pulse.The mechanism of the TTD introduced by the grating and the formation of the relative time delay （RTD） in the noncollinear correlation system are analyzed in detail.By using our system,we successfully measured the temporal duration of picosecond laser pulses,and a time resolution of ～0.047 ps is obtained at 1047 nm.The impact of the grating dispersion and the second harmonic beam walk-off effect on the measurement are considered.
