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Diffraction efficiency

About: Diffraction efficiency is a research topic. Over the lifetime, 10320 publications have been published within this topic receiving 158298 citations.


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Journal ArticleDOI
TL;DR: In this paper, the phase conjugate reflectivity and diffraction efficiency were measured for both the reflection and transmission grating cases for a Nd:YAG amplifier using orthogonally polarised pump beams of pulse duration 16 ns.

48 citations

Journal ArticleDOI
TL;DR: In this article, the authors report on the fabrication and testing of linear transmission Fresnel zone plates for hard x-rays, which are generated by electron beam lithography and chemical wet etching of 〈110〉 oriented silicon substrates.
Abstract: We report on the fabrication and testing of linear transmission Fresnel zone plates for hard x rays. The diffractive elements are generated by electron beam lithography and chemical wet etching of 〈110〉 oriented silicon substrates. By tilting the cylindrical lenses with respect to the x-ray beam, the effective path through the phase shifting zones can be varied. This makes it possible to optimize the diffraction efficiency over a wide range of photon energies, and to obtain effective aspect ratios not accessible with untilted optics. The diffraction efficiency of such a lens was measured as a function of the tilt angles for various energies between 8 and 29 keV. Values close to the theoretical limit were obtained for all energies. Because of the coherence preserving properties of diffractive optics, the method opens up opportunities for experiments using coherent hard x rays.

48 citations

Journal ArticleDOI
TL;DR: The dispersion characteristics of a diffractive micro-Fresnel lens (MFL) which is mass-produced for a laser diode collimator are examined for novel applications in this paper.
Abstract: The dispersion characteristics of a diffractive micro-Fresnel lens (MFL) which is mass-produced for a laser diode collimator are examined for novel applications. The MFL's resolving power (Rayleigh criterion for resolution) at the design wavelength is calculated to be comparable to that of conventional dispersing prisms of the same size. A simple spectrometer with an MFL (4.5 mm diameter, 14.83 mm focal length at 0.78 μm design wavelength) and a movable pinhole (PH), is fabricated. The optimum PH diameter for both resolving power and light efficiency is 5 m, and the resolution and efficiency at the design wavelength are estimated to be 3.7 nm and 85%, respectively. The measurable spectral range determined from both the diffraction efficiency and the free spectral range of the MFL almost covers the entire visible region. The absorption spectrum of KMnO4 solution is roughly obtained using the spectrometer. The space between the MFL and the PH, and the PH's movable length, which are required for spectroscopy, are as short as 20 and 7 mm, respectively. The simple and straight-line-structured spectroscopic system utilizing a more cost-efficient MFL may lead to the realization of less expensive and compact spectrometers.

48 citations

Journal ArticleDOI
TL;DR: More than 97% flat-top diffraction efficiency in the -1st-order TE polarization over a 110 nm wavelength range around 800 nm in an all-dielectric grating is designed by a simulated annealing algorithm and the Fourier mode method, providing a way for high-efficiency chirped-pulse amplification to be used in an ultrashort high-power pulse laser system based on all- dielectric gratings.
Abstract: More than 97% flat-top diffraction efficiency in the -1st-order TE polarization over a 110 nm wavelength range around 800 nm in an all-dielectric grating is designed by a simulated annealing algorithm and the Fourier mode method. Its band is near to the maximum bandwidth provided by a dielectric high-reflectivity mirror under the match layer. This result will provide a way for high-efficiency chirped-pulse amplification to be used in an ultrashort high-power pulse laser system based on all-dielectric gratings. Furthermore, an effective method for broadband high-efficiency all-dielectric grating design is presented in this Letter.

48 citations

Journal ArticleDOI
TL;DR: In this paper, the room temperature, water-cooled, diode pumped Tm:YLF laser head was elaborated and examined for pumping the fiber coupled (0.2 mm core diameter) 25-W laser diode bar emitting at 792-nm wavelength.
Abstract: The room-temperature, water-cooled, diode pumped Tm:YLF laser head was elaborated and examined. For pumping the fiber coupled (0.2 mm core diameter) 25-W laser diode bar emitting at 792-nm wavelength was deployed. Near 5 W of CW output power and 25% slope efficiency was demonstrated in a short, 70-mm long resonator. Tuning in 1845–1935 nm wavelength range by means of 2-plate Lyot filter was demonstrated only in free-running regime. The fused silica acousto-optic modulator with above 80% diffraction efficiency for 25-W power of RF was deployed as the Q-switch for such a laser. In the best case of Q-switching regime, up to 10-mJ output energy with 47-ns pulse duration, 220 kW peak power was demonstrated for 133 Hz. For higher repetition rate of 2 kHz, 12 kW peak power with 2.5 W of average power was achieved.

48 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202391
2022188
2021167
2020223
2019259
2018259