Hong Li

In this study, a multi-objective optimization method based on response surface methodology (RSM) is proposed for precision fabrication of tapered fiber probes. We systematically decouple the effects of process parameters on the tip diameter and taper angle of the probes through experimental design. A Plackett–Burman (P-B) screening identified four dominant control factors with significance ranking: laser power > feeding speed > acceleration > acceleration duration. The Box-Behnken design (BBD) experiment established robust predictive models for tip diameter (R ² =0.9127) and taper angle (R ² =0.9211), enabling simultaneous optimization of conflicting geometric targets. Optimized parameters reduced fabrication errors to sub-7% with ≥17% accuracy improvement. This method effectively transforms empirical craftsmanship into quantifiable engineering processes and provides scientifically rigorous insights into parameter optimization during the fabrication of fiber micro-structured devices.

In response to the increasing demand for accurate monitoring of three-dimensional positional transformation of target loads, and also to overcome the errors due to the deformation of the support structure itself at the point of deployment of multiple devices. The present study proposes a compensation method for three-dimensional optical angle measurement systems based on multi-device collaboration. Three-dimensional vectors are used to characterize the positional transformation of the target load, and the coordinates of the spot on the detection surface of the goniometers are derived. Based on the spot coordinates of the three goniometers, the theoretical attitude transformation value of the target load is inverted by means of the Levenberg-Marquardt algorithm. The target attitude transformation values are compared between the three goniometer devices for cooperative compensation monitoring and between only two devices for monitoring, respectively. The average errors of the angular measurements in the a, b, and c directions are less than 0.044″, 1.069″, and 0.03″, respectively, which are 6.1, 11.6, and 7 times lower than those before compensation. After verification of the simulation of the actual situation, the changes in the relevant variables of the goniometer system and the measured changes in the reference autocollimator are consistent with the accuracy of the reference autocollimator. It is concluded that the measurement computing accuracy of the goniometer system is not lower than that of the reference autocollimator, which verifies the practicability and effectiveness of the compensation method proposed.

In this paper, we propose a delayed-focusing type micro-angle measurement optical system based on the Cassegrain structure (cassette structure), analyze the basic cassette structure and the Galilean laser beam expanding system, and determine the primary and secondary mirror structure as a reflective focusless system as a determining module. This focusless system emits and receives parallel light, and the light source and detector separated by the beam splitter are designed as replaceable modules. Additionally, the imaging quality of the system can be optimized, or the effect of meeting different imaging requirements can be achieved, by changing the number and type of corrective mirrors and the parameters of the specific glass elements in the replaceable modules. After the final optimization, the radius of the imaging spot of the combined mirror group can be limited to 6.1 µm; the modulation transfer function is better than 0.6 at 100 lp/mm; the difference between the meridian and the arc-vector curves is less than 0.1; and the theoretical angular accuracy reaches 0.2″. The delayed-focusing system structure is analyzed under different temperature fields to provide guidance for the design of the subsequent structure temperature control. Comparison and analysis with commonly used angle measurement optical systems are also made. It is concluded that the structure meets the requirements for use in the on-orbit environment, completes the reuse of the established structural modules, and further saves the manufacturing cost, which provides a feasible solution to the problem of monitoring the small angular changes in the field of space.

A tapered-optical fiber tip coupler for the excitation of capillary whispering gallery modes (WGMs) is proposed. The phase matching theory and spectral features are analyzed. The light transmission characteristics and cross-sectional mode fields of the coupler are simulated. The impact of fabrication tolerance on excited WGM is studied, and the structure is fabricated based on the simulation results. It has been experimentally verified that this structure can excite the WGM resonance of capillaries of various sizes, with the highest quality factor (Q factor) of 3.6×103 and refractive index sensitivity of 22.28 nm/RIU. The resonant coupler is not fragile, large fabrication tolerance, and can excite WGM in capillaries of different sizes, which can provide a new means of detection in the field of capillary biochemical sensing.

The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed 《中国光学》的前身是1985年创办的《中国光学与应用光学文摘》，当时是国内光学领域唯一的检索刊物。2008年底《中国光学与应用光学文摘》转型更名为《中国光学与应用光学》期刊，刊载内容突破了文摘的限制，正式成为学术刊物。

An in-line optical fiber Mach–Zehnder interferometric (MZI) sensor is proposed and experimentally demonstrated for magnetic field measurement. The fabrication mechanism of the optical fiber microstructures by CO₂ laser is described in detail. The sensor with symmetrical structure is fabricated by splicing a 7-mm length of seven-core fiber and two fiber peanuts, which is encapsulated with magnetic fluid in the capillary. The transmission spectrum of the MZI is modulated by the refractive index of the magnetic fluid, which is affected by the magnetic field. The experimental results indicate that the mode interference is sensitive to the magnetic field and different dips of the interference spectrum have different sensitivities. Hence, simultaneous measurement of the temperature and magnetic field can be achieved by simultaneously monitoring two different dips. The sensitivities of the magnetic field and temperature can reach up to 0.062 nm / Gs and 0.081 nm / ° C, respectively. The proposed Mach–Zehnder interference sensor has a more compact structure, simple manufacturing process, and high reliability, which would find potential applications in weak magnetic sensing fields.