Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： Ultra-short ultra-intense laser provides unprecedented experimental tools and extreme physical conditions to explore frontier secrets of nature. Recently, multistep pulse compressor (MPC) was proposed to break through the limitation of the size and damage threshold of the grating in the compressor during the realization of higher peak power laser. In the MPC methods, beam smoothing in the pre-compressor is a very important process. Here, beam smoothing based on prism pair were studied technically, in which both the spatial profiles and the spectral dispersive properties were analyzed in detail. The simulation results show clearly that the prism pair can effectively smooth the laser beam. Furthermore, the beam smoothing is much more efficiency with shorter separated distance if two prism pairs are arranged to induce spatial dispersion at one direction or two directions. The results of beam smoothing here will help the optimized optical designs in all PW laser systems to improve their output and running safety.
Peer Review Status:
Awaiting Review
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： Whispering-gallery mode crystalline resonators currently maintain the best quality factor (Q) record, however, compact on-chip packaging is still a challenge although various coupling architectures have been developed. Here, a chemical etching method is proposed to fabricate a miniaturized tapered fiber waveguide on silicon substrate. The Marangoni effect is implemented to reduce the surface roughness of the cone region. The optical loss of 0.1 dB/mm is obtained, and the Q of on-chip crystalline resonator exceeds 108. Additionally, TEC is implanted in the package to actively customize the temperature, and the temperature response of 18 pm/K is consistent with the theoretical calculation.
Peer Review Status:Awaiting Review
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： The sandwich structure as the core layer of PDMS resonator is proposed for single-axis magnetic sensor with high sensitivity. The small Young's modulus of flexible material corresponds to larger variation, resulting in a highly sensitive magnetic response. The sandwich structure pre-set magnetic field provides directional sensing feature. The experimental results show that the redshift sensitivity of 1.08 nm/mT and the blueshift sensitivity of 1.12 nm/mT in the unshielded environment, which is attributed to slight variation in PDMS Young's modulus. At 1.4 kHz, a minimum detectable magnetic field of 0.96 nT Hz-1/2 is realized.
Peer Review Status:Awaiting Review
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： The peak power improvement and running safety of petawatt (PW) lasers are limited by laser-induced damage of optical components with limited sizes and damage thresholds. Diffraction gratings in pulse compressors have been the shortest stave of PW lasers up to now, as to manufacture a high quality meter-sized grating remains particularly challenging. Here, the asymmetric four-grating compressor (AFGC) with asymmetric configuration is proposed for PW lasers to increase the maximum bearable output pulse energy and running safety without neither additional optical component nor extra control in comparison to a traditional Treacy four-grating compressor (TFGC) with symmetric configuration. In AFGC, suitable spatial dispersion can be introduced in the output laser beam which is able to decrease the laser spatial intensity modulation (LSIM) of the output beam on the final grating. The introduced spatial dispersion can be automatically compensated at the focal plane by using the spatiotemporal focusing technique. Based on this simple AFGC design, not only the damage risk of the final grating can be reduced, but also the maximum output pulse energy can be improved by about 1.8 times theoretically. As an example, 100 PW output power can be achieved theoretically by using the AFGC with an input beam size of 550*700 mm2.
Peer Review Status:Awaiting Review
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： A multistage smoothing multistep pulse compressor (MPC) based on a single-pass single-grating-pair (SSGP) main compressor is proposed to simplify the entire petawatt (PW) compressor. Only one grating pair with relatively long distance is used to generate the same amount of spectral dispersion in the main compressor compared with a four-grating main compressor. As the SSGP induces the largest spatial dispersion, it can introduce the best beam-smoothing effect to the laser beam on the last grating. When considering the diffraction loss of only two gratings, the total compression efficiency of the SSGP main compressor is even larger than that of a four-grating main compressor. Furthermore, the spatiotemporal aberration induced by single-grating-pair can be compensated effectively by using deformable mirrors, however it is difficult or complicated to be well compensated in a four-grating compressor. Approximately 50-100 PW laser pulses can be obtained using this SSGP-based multistage smoothing MPC with a single laser beam
Peer Review Status:Awaiting Review
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