Femtosecond tunable light source with variable repetition rate between 640 kHz and 41 MHz with 130 dB temporal pulse contrast ratio

In this paper, pulse contrast was measured for femtosecond lasers with low-repetition-rate (40 Hz) using optical Kerr gate as a sampler. The results show that, without attenuator, dynamic range as high as 104 was achieved, with a scanning range of 126 ps and a temporal sampling interval of 6.3 fs. Moreover, the method suits for measuring laser pulse contrast in wide spectrum range.

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Independent and continuous third-order dispersion compensation using a pair of prisms

High Power Laser Science and Engineering ◽

10.1017/hpl.2014.40 ◽

2014 ◽

Vol 2 ◽

Author(s):

Qingwei Yang ◽

Xinglong Xie ◽

Jun Kang ◽

Haidong Zhu ◽

Ailin Guo ◽

...

Keyword(s):

Pulse Duration ◽

Dispersion Compensation ◽

Contrast Ratio ◽

Group Delay Dispersion ◽

Third Order ◽

Third Order Dispersion ◽

Wide Range ◽

Laser Systems ◽

Order Dispersion ◽

Pulse Contrast

Abstract The dispersion of a pair of prisms is analyzed by means of a ray-tracing method operating at other than tip-to-tip propagation of the prisms, taking into consideration the limited spectral bandwidth. The variations of the group delay dispersion and the third-order dispersion for a pair of prisms are calculated with respect to the incident position and the separation between the prisms. The pair of prisms can provide a wide range of independent and continuous third-order dispersion compensation. The effect of residual third-order dispersion on the pulse contrast ratio and pulse duration is also calculated. The residual third-order dispersion not only worsens the pulse contrast ratio, but also increases the pulse duration to the hundreds of femtosecond range for a tens of femtosecond pulse, even when the residual third-order dispersion is small. These phenomena are helpful in compensating for the residual high-order dispersion and in understanding its effect on pulse contrast ratios and pulse durations in ultrashort laser systems.

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Intra-Burst Temporal Pulse Contrast of a High-Power Post-Compressed Picosecond Yb:YAG Laser

10.1364/cleo_si.2021.sth2i.5 ◽

2021 ◽

Author(s):

Anne-Lise Viotti ◽

Skirmantas Alisauskas ◽

Esmerando Escoto ◽

Henrik Tünnermann ◽

Katharina Dudde ◽

...

Keyword(s):

High Power ◽

Pulse Contrast ◽

Temporal Pulse

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Coherent quasi-CW 153-nm light source at high repetition rate

10.1117/12.910254 ◽

2012 ◽

Author(s):

Yutaka Nomura ◽

Yoshiaki Ito ◽

Akira Ozawa ◽

Xiaoyang Wang ◽

Chuangtian Chen ◽

...

Keyword(s):

Light Source ◽

Repetition Rate ◽

High Repetition Rate ◽

High Repetition

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Adaptive Image Rendering Using a Nonlinear Mapping-Function-Based Retinex Model

Sensors ◽

10.3390/s19040969 ◽

2019 ◽

Vol 19 (4) ◽

pp. 969

Author(s):

JongGeun Oh ◽

Min-Cheol Hong

Keyword(s):

Light Source ◽

State Of The Art ◽

Contrast Ratio ◽

Mapping Function ◽

Experimental Results ◽

Nonlinear Mapping ◽

Low Light ◽

Reconstruction Process ◽

Image Rendering ◽

The Relationship

This paper introduces an adaptive image rendering using a parametric nonlinear mapping-function-based on the retinex model in a low-light source. For this study, only a luminance channel was used to estimate the reflectance component of an observed low-light image, therefore halo artifacts coming from the use of the multiple center/surround Gaussian filters were reduced. A new nonlinear mapping function that incorporates the statistics of the luminance and the estimated reflectance in the reconstruction process is proposed. In addition, a new method to determine the gain and offset of the mapping function is addressed to adaptively control the contrast ratio. Finally, the relationship between the estimated luminance and the reconstructed luminance is used to reconstruct the chrominance channels. The experimental results demonstrate that the proposed method leads to the promised subjective and objective improvements over state-of-the-art, scale-based retinex methods.

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