针对相移结构光中相位计算环节，提出了一种基于一维查找表的相位实时解码算法。首先根据相位计算公式中的反正切函数性质，得到四个象限之间的相位转化关系。基于得到的转换关系，使用线性函数将第一象限中的所有坐标点映射至某个离散整数区间中，结合该区间与线性函数提前建立相位的一维查找表。在相位计算过程中，首先利用相关信息计算一维查找表的索引，直接获取相位值，然后利用线性插值法与相位转换关系调整该相位值，得到最终的真实相位。通过实验验证了所提算法的有效性，与使用传统相位计算方法相比，本文提出的方法最快可提升3.97倍，使用线性插值后，相位精度可达 ${10^{ - 8}}$。与传统的多项式逼近算法相比，该算法速度提升了1.29倍；与传统的一维查找表算法相比，该算法速度提升了1.22倍。

An approach to generate high-speed and wideband frequency shift keying (FSK) signals based on carrier phase-shifted double sideband (CPS-DSB) modulation is proposed and experimentally validated. The core part of the scheme is a pair of cascaded polarization-sensitive LiNbO₃ Mach–Zehnder modulators and phase modulators, whose polarization directions of the principal axes are mutually orthogonal to each other. A proof-of-concept experiment is carried out, where a 0.5 Gb/s FSK signal with the carrier frequencies of 4 and 8 GHz and a 1 Gb/s FSK signal with the carrier frequencies of 8 and 16 GHz are generated successfully.

Suppressing nonlinear effects in high-power fiber lasers based on fiber gratings has become a hotspot. At present, research is mainly focused on suppressing stimulated Raman scattering in a high-power fiber laser. However, the suppression of spectral broadening, caused by self-phase modulation or four-wave mixing, is still a challenging attribute to the close distance between the broadened laser and signal laser. If using a traditional fiber grating with only one stopband to suppress the spectral broadening, the signal power will be stripped simultaneously. Confronting this challenge, we propose a novel method based on phase-shifted long-period fiber grating (PS-LPFG) to suppress spectral broadening in a high-power fiber master oscillator power amplifier (MOPA) laser system in this paper. A PS-LPFG is designed and fabricated on 10/130 passive fiber utilizing a point-by-point scanning technique. The resonant wavelength of the fabricated PS-LPFG is 1080 nm, the full width at half maximum of the passband is 5.48 nm, and stopband extinction exceeds 90%. To evaluate the performance of the PS-LPFG, the grating is inserted into the seed of a kilowatt-level continuous-wave MOPA system. Experiment results show that the 30 dB linewidth of the output spectrum is narrowed by approximately 37.97%, providing an effective and flexible way for optimizing the output linewidth of high-power fiber MOPA laser systems.

A novel phase-shifted long-period fiber grating (PS-LPFG) for the simultaneous measurement of torsion and temperature is described and experimentally demonstrated. The PS-LPFG is fabricated by inserting a pre-twisted structure into the long-period fiber grating (LPFG) written in single-mode fiber (SMF). Experimental results show that the torsion sensitivities of the two dips are ?0.114 nm/(rad/m) and ?0.069 nm/(rad/m) in the clockwise direction, and ?0.087 nm/(rad/m) and ?0.048 nm/(rad/m) in the counterclockwise direction, respectively. The temperature sensitivities of the two dips are 0.057 nm/°C and 0.051 nm/°C, respectively. The two dips of the PS-LPFG exhibit different responses to torsion and temperature. Simultaneous measurement of torsion and temperature can be implemented using a sensor. The feasibility and stabilization of simultaneous torsion and temperature measurement have been confirmed, and hence this novel PS-LPFG demonstrates potential for fiber sensing and engineering applications.