LAOP 2022's 191 attendees heard from five plenary speakers, along with 28 keynotes, 24 invited talks, and 128 presentations, consisting of both oral and poster sessions.

This paper examines the residual deformation of functional gradient materials (FGMs) manufactured by laser directed energy deposition (L-DED), proposing a forward and reverse strain calibration method that accounts for scan direction-dependent effects. From the multi-scale model of the forward process, the calculations of inherent strain and residual deformation are carried out for each scanning strategy, using the orientations of 0, 45, and 90 degrees, respectively. Experiments using L-DED, revealing residual deformation, were instrumental in the inverse calibration of inherent strain using the pattern search method. Rotation matrices and averaging techniques allow the attainment of the final, inherent strain calibrated at zero degrees. Lastly, the definitively calibrated inherent strain is incorporated into the model of the rotational scanning strategy. In the verification stage, the experiments exhibited a strong alignment with the predicted residual deformation trend. This work allows for the prediction of the residual deformation of FGMs and serves as a valuable reference.

Future trends in Earth observation technology are evident in the integrated acquisition and identification of both elevation and spectral information from observed targets. read more Within this study, a set of airborne hyperspectral imaging lidar optical receiving systems is constructed and examined for its ability to detect the infrared band echo signal of the lidar system. Each avalanche photodiode (APD) detector in the set is individually configured to capture the echo signal from the 800-900 nm wavelength band, a signal of weak intensity. The APD detector's photosensitive surface, a circle, possesses a radius of 0.25 millimeters. The laboratory-based optical focusing system demonstration on the APD detector indicated that the image plane size of the optical fiber end faces across channels 47 to 56 was about 0.3 mm. read more Results affirm the reliability of the self-designed APD detector's optical focusing system. The 800-900 nm band echo signal is coupled to the matching APD detector through the fiber array, using the focal plane splitting technology of the array, allowing for a series of performance tests on the detector. In field tests, the ground-based platform's APD detectors in all channels successfully executed remote sensing measurements spanning 500 meters. The newly developed APD detector, incorporated into airborne hyperspectral imaging lidar systems, solves the challenge of hyperspectral imaging under weak light conditions, resulting in precise ground target detection in the infrared band.

The combination of digital micromirror device (DMD) and spatial heterodyne spectroscopy (SHS), termed DMD-SHS modulation interference spectroscopy, leverages a DMD for secondary interferometric data modulation, ultimately realizing a Hadamard transform. Spectrometer performance gains in SNR, dynamic range, and spectral bandwidth are enabled by DMD-SHS, maintaining the benefits of conventional SHS implementation. The spatial layout of the DMD-SHS optical system, and the performance expected of its components, are both more demanding than those of a standard SHS, due to the increased complexity of the DMD-SHS. With the DMD-SHS modulation mechanism as our framework, a detailed analysis of the functions and specific design requirements of each component was performed. An experimental device for DMD-SHS was fashioned according to the specifications derived from the potassium spectra. Potassium lamp and integrating sphere detection experiments on the DMD-SHS device yielded a spectral resolution of 0.0327 nm across a spectral range of 763.6677125 nm, powerfully demonstrating the feasibility of DMD and SHS combined modulation interference spectroscopy.

Laser scanning measurement systems play a crucial role in precision measurement due to their non-contacting and low-cost features; however, conventional methods and systems lack accuracy, efficiency, and adaptability. This study presents a 3D scanning system, characterized by the use of asymmetric trinocular vision and a multi-line laser, to bolster measurement performance. This paper investigates the innovative system, as well as its underlying design, operating principle, and 3D reconstruction method. Subsequently, a multi-line laser fringe indexing method is demonstrated. It incorporates K-means++ clustering and hierarchical processing, optimizing speed while maintaining accuracy. This aspect is pivotal to 3D reconstruction. A multitude of experiments were designed to probe the capabilities of the developed system; the results corroborated its success in fulfilling measurement needs in terms of adaptability, accuracy, effectiveness, and robustness. In complex measurement settings, the engineered system yields superior outcomes than commercial probes, enabling measurement accuracy as precise as 18 meters.

The effectiveness of digital holographic microscopy (DHM) in evaluating surface topography is well-established. The combination leverages the high lateral resolution of microscopy, coupled with the high axial resolution achievable via interferometry. This paper's focus is on the presentation of DHM with subaperture stitching, applied to tribology. A significant benefit of the developed methodology is its capacity to inspect large surface areas by combining and stitching together multiple measurements. This advantage is evident when evaluating tribological tests, such as those on a tribological track within a thin layer. Compared to the conventional four-profile measurement performed by a contact profilometer, the track measurement across the entire surface provides more comprehensive parameters leading to a richer tribological test analysis.

A 155-meter single-mode AlGaInAs/InP hybrid square-rectangular laser serves as the seeding source for the demonstrated multiwavelength Brillouin fiber laser (MBFL) with a switchable channel spacing. A 10-GHz-spaced MBFL is created using a feedback path within a highly nonlinear fiber loop, which is part of the scheme. In a subsequent loop of highly nonlinear fiber, employing cavity-enhanced four-wave mixing, MBFLs with spacings from 20 GHz to 100 GHz, at 10 GHz intervals, were generated with the aid of a tunable optical bandpass filter. Every switchable spacing successfully produced more than 60 lasing lines, characterized by an optical signal-to-noise ratio exceeding 10 dB. Through testing, the stability of the MBFLs' channel spacing and total output power has been verified.

A snapshot imaging Mueller matrix polarimeter, incorporating modified Savart polariscopes (MSP-SIMMP), is described. Employing spatial modulation, the MSP-SIMMP's polarizing and analyzing optics capture all Mueller matrix components of the sample, translating them into the interferogram. The analysis of the interference model encompasses its reconstruction and calibration processes. To underscore the practicality of the proposed MSP-SIMMP, both numerical simulation and a laboratory experiment on a design example are presented. The straightforward calibration process of the MSP-SIMMP is a noteworthy benefit. read more The proposed instrument's design, in contrast to conventional Mueller matrix polarimeters incorporating rotating elements, possesses an advantage in terms of simplicity, compactness, instantaneous imaging, and a stationary operational mode with no moving components.

Multilayer antireflection coatings (ARCs) are typically employed in solar cells to amplify the photocurrent generated at a normal angle of incidence. The reason outdoor solar panels are often placed to receive strong midday sunlight at a nearly vertical angle is due to their design considerations. Yet, within indoor photovoltaic systems, the light direction fluctuates significantly with adjustments in the relative position and orientation of the device to the light source; this makes predicting the incidence angle quite difficult. Within this study, we analyze a method for designing ARCs compatible with indoor photovoltaic applications, paying particular attention to the indoor lighting environment, distinct from the exterior conditions. We present an optimized design strategy for solar cells, seeking to elevate the average photocurrent generated when the cell experiences randomly-directional irradiance. To create an ARC for organic photovoltaics, projected to perform well indoors, we implement the suggested method and numerically contrast the ensuing performance with that originating from a conventional design method. Our design strategy proves effective, according to the results, for achieving excellent omnidirectional antireflection, enabling the creation of practical and efficient ARCs suitable for indoor use.

A sophisticated technique for nano-local etching on quartz surfaces is being studied. Surface protrusions are posited to amplify evanescent fields, thereby accelerating the process of quartz nano-local etching. A method has been developed to minimize etch product accumulation in rough surface troughs, while simultaneously optimizing the surface nano-polishing process. The evolution of the quartz surface profile's characteristics is shown to depend on the initial surface roughness, the refractive index of the molecular chlorine medium in contact with the quartz, and the wavelength of the incident radiation.

Dense wavelength division multiplexing (DWDM) system effectiveness is critically compromised by the issues of dispersion and attenuation. The optical spectrum experiences pulse broadening due to dispersion, and attenuation contributes to the deterioration of the optical signal. This paper investigates the potential of dispersion compensation fiber (DCF) and cascaded repeaters to overcome linear and nonlinear challenges in optical transmission. The investigation uses two modulation formats (carrier-suppressed return-to-zero [CSRZ] and optical modulators) and two different channel spacings (100 GHz and 50 GHz).