Xiaopeng Shao

Xiaopeng Shao
Xidian University · School of Physics and Optoelectronic Engineering

PhD

About

153
Publications
12,083
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793
Citations

Publications

Publications (153)
Article
A compact, highly sensitive, and cost-effective photoacoustic spectroscopic sensor for multiple trace gas detection was reported with a self-designed compact distributed feedback laser array and a 2-channel dual phase field programmable gate array based digital lock-in amplifier, only twentieth in size and weight of the commercial instruments. The...
Article
In the power industry, sulfur hexafluoride (SF 6 ) as an insulating gas is widely used in gas-insulated switchgears (GISs). Owing to the latent inner insulation defects of GIS, various SF 6 gas decompositions are generated in the process of partial superheating and partial discharge (PD). The decomposition components and concentrations are differen...
Article
Full-text available
Acoustic detectors constitute a key factor of photoacoustic spectroscopy configuration, which is an ultrasensitive gas sensing method. This review aimed to discuss the recent development of acoustic detectors, including capacitive microphone, quartz tuning forks, and optical microphone. An overview of their applications for sensitive, selective, an...
Article
Analyzing the polarimetric properties of the reflected light is a simple, fast, and low-cost approach to recover shape information, but no reported method can accurately recover surface shape from non-Lambertian object in natural conditions with a single view. Another major issue is the lack of effective methods to address azimuth ambiguity during...
Article
Full-text available
Photoacoustic spectroscopy (PAS), as a nondestructive method, permits high sensitivity and selectivity in trace gas detection fields. Advances in differential PAS configurations have dramatically suppressed the background noise and triggered the detectivity improvement. A detailed review on the development of differential photoacoustic gas sensors...
Article
Full-text available
Fourier ptychography (FP) is geared toward high-resolution imaging with a large field of view efficiently. In the original illumination-based FP scheme, the aberrations in optical systems can be well reconstructed, which plays a prominent role in simple and compact optical arrangements. Unfortunately, the reconstruction strategy for recovering an o...
Article
Full-text available
The determination of toxic or harmful gases in industrial parks constitutes a challenge for monitoring exhaust contaminants due to the features of complex compositions and ubiquity. Blackbody sources play an important role in simultaneous detection of multiple gas species in the presence of cross-interfering absorption lines thanks to their effecti...
Article
Full-text available
In SF6 insulated high-voltage gas power systems, H2O is the most problematic impurity which not only decreases insulation performance but also creates an acidic atmosphere that promotes corrosion. Corrosion damages electrical equipment and leads to leaks, which pose serious safety hazards to people and the environment. A QEPAS-based sensor system f...
Article
Full-text available
Multi-height phase retrieval introduces different object-to-detector distances for obtaining phase diversity measurements. In the acquisition process, the slow-varying phase information, however, cannot be converted to intensity variations for detection. Therefore, the low-frequency contents of the phase profile are lost during acquisition and cann...
Article
Full-text available
A ppb-level H2S and CO photoacoustic spectroscopy (PAS) gas sensor was developed by using a two-stage commercial optical fiber amplifier with a full output power of 10 W. Two near-infrared diode lasers with the central wavenumbers of 6320.6 cm⁻¹ and 6377.4 cm⁻¹ were employed as the excitation laser source. A time-division multiplexing method was us...
Article
A non-local patch regression (NLPR) denoising-enhanced differential broadband photoacoustic (PA) sensor was developed for the high-sensitive detection of multiple trace gases. Using the edge preservation index (EPI) and signal-to-noise ratio (SNR) as a dual-criterion, the fluctuation was dramatically suppressed while the spectral absorption peaks w...
Article
Speckle correlation imaging (SCI) has found tremendous versatility compared with other scattering imaging approaches due to its single-shot data acquisition strategy, relatively simple optical setup, and high-fidelity reconstruction performance. However, this simplicity requires SCI experiments to be performed strictly in a darkroom condition. As b...
Article
Phase shifting profilometry normally requires at least three-frame fringe patterns to extract the phase of objects. In the dynamic measurement field, it is desirable to reduce the number of fringe patterns and eliminate the phase-shifting error caused by the moving of the test object between fringe patterns. In the field of interferometry, the opti...
Article
Underwater imaging method based on polarization information is extremely popular due to its ability to effectively remove the backscattered light. The Stokes vector contains the information of both the degree and angle of polarization of the light wave. However, this aspect has been rarely utilized in image reconstruction. In this study, an underwa...
Article
This paper presents a near-infrared (NIR) monocular 3D computational polarization imaging method to directly reconstruct the shape of surfaces exhibiting nonuniform reflectance. A reference gradient field is introduced to the weight constraints for globally correcting the ambiguity of the surface normal for a target with nonuniform reflectance. We...
Article
Diffractive zone plate optics uses a thin micro-structure pattern to alter the propagation direction of the incoming light wave. It has found important applications in extreme-wavelength (extreme ultraviolet or soft X-ray) imaging where conventional refractive lenses do not exist. The resolution limit of zone plate optics is determined by the small...
Article
Full-text available
Circular polarization (CP) memory is a well-known phenomenon whereby natural light becomes partially circularly polarized after scattering by water spray several times, and the circularly polarized state can be well preserved within a certain propagation distance. In this study, a CP imaging method combined with the multi-scale analysis in the freq...
Article
Full-text available
The existence of a signal baseline due to a variety of reasons in a photoacoustic (PA) gas measurement system is a common phenomenon. One major component is the absorption of optical windows in an enclosed PA cell. This work explores the relation between the background signal and the thermoelastic effect inside the windows by modelling the pressure...
Preprint
Full-text available
Diffractive zone plate optics uses a thin micro-structure pattern to alter the propagation direction of the incoming light wave. It has found important applications in extreme-wavelength imaging where conventional refractive lenses do not exist. The resolution limit of zone plate optics is determined by the smallest width of the outermost zone. In...
Article
Scattering limits the acquisition of object information and reduces the probe depth. Imaging correlography method utilizing scattering light has shown its advantage in visualization deep through dynamic multiple scattering medium. However, there is a lack of boundary condition to use it specifically. Here, we propose a new criterion for imaging cor...
Preprint
Full-text available
Analyzing the polarimetric properties of the reflected light is a simple, fast, and low-cost approach to recover shape information, but no reported method can accurately recover surface shape from non-Lambertian object in natural conditions with a single view. Another major issue is the lack of effective method to address azimuth ambiguity during t...
Article
Fringe projection three-dimensional (3D) measurement technique is an effective technique to measure 3D shape of objects, in which phase retrieval is an important procedure. To overcome the need of pre-filtering process in the existing single-frame methods, this paper proposes a novel method to extract phase distribution solely from one-frame fringe...
Article
Full-text available
Enhancement of trace gas detectability using photoacoustic spectroscopy requires the effective suppression of strong background noise for practical applications. An upgraded infrared broadband trace gas detection configuration was investigated based on a Fourier transform infrared (FTIR) spectrometer equipped with specially designed T-resonators an...
Article
Polarization imaging is a promising technology with great potential. Besides light intensity, it provides information in another dimension, polarization. When imaging through water, two frames of the target at two orthogonally polarized states, Imax and Imin, are needed. In most experiments, they are determined by searching for the darkest and brig...
Article
The presence of an inhomogeneous scattering medium has brought great challenges to optical imaging and detection in many fields. In this work, we propose a speckle-autocorrelation based orthogonal projection algorithm to detect the flipped target hidden behind a scattering layer in X-Z plane and Y-Z plane. By calculating the speckle autocorrelation...
Article
A robust method for efficient spatial separation optical imaging through scattering media regardless of the three-dimensional (3D) optical memory effect is proposed. In this method, the problems of imaging dealiasing, decomposition, and separation of speckle patterns are solved by employing independent component analysis. Multitarget imaging behind...
Article
The fringe projection profilometry (FPP) has obtained increasing popularity in the field of industrial automation, inverse engineering and graphics. Recent literature reveals that the non-ideal system point spread function (PSF) in FPP will cause phase error in the area around the discontinuous edge. Existing error reduction methods need to detect...
Chapter
A novel framework of optical SWaP (Size, Weight, and Power/Price) computational imaging method is proposed to solve the problem of large size, heavy weight, and high power consumption in traditional military optoelectronic weapon equipment. The key point of traditional optical system design is focused on the various geometrical aberration correctio...
Article
Full-text available
Heavy metal (HM) contamination in soil is a threat to human health and environmental safety. This paper presents an infrared photoacoustic spectroscopic non-destructive testing for HM evaluation by a robust customized photoacoustic spectrometric system. Cadmium (Cd) was selected as the target contamination which was blended in soil samples. A two-l...
Preprint
A robust method and strategy for efficient full field-ofview and depth separation optical imaging through scattering media regardless of the three-dimensional (3D) optical memory effect are proposed. In this method, the problem of imaging de-aliasing, decomposition, and separation of speckle patterns are solved taking advantages of the spatial deco...
Article
Full-text available
Recent advancements in whole slide imaging (WSI) have moved pathology closer to digital practice. Existing systems require precise mechanical control, and the cost is prohibitive for most individual pathologists. Here we report a low-cost and high-throughput WSI system termed OpenWSI. The reported system is built using off-the-shelf components, inc...
Article
Light passing through scattering media will be strongly scattered and diffused into a complex speckle pattern, which contains most of the spatial information and color information of the objects. Although various technologies have been proposed to realize color imaging through scattering media, current technologies are still inflexible, since they...
Preprint
Full-text available
Recent advancements in whole slide imaging (WSI) have moved pathology closer to digital practice. Existing systems require precise mechanical control and the cost is prohibitive for most individual pathologists. Here we report a low-cost and high-throughput WSI system termed OpenWSI. The reported system is built using off-the-shelf components inclu...
Preprint
Full-text available
In this study, we demonstrate first, to the best of our knowledge, robust and dynamically polarization-controlled tunable-high-Q PIT in designed nanostructures metasurface, whose sharp resonance is guaranteed by design and protected against large geometrical imperfections. By employing the explicit analysis of near-field characteristic in the recip...
Article
In this study, a coaxial and multi-aperture polarization imaging system was designed to obtain dehazed images under bad weather conditions, which could effectively utilize polarization information. The system can capture four polarization azimuth images simultaneously by integrating four polarizers with different transmission directions in front of...
Article
Plasmon-induced transparency (PIT) in nanostructures has been intensively investigated; however, there are no known metasurface nanostructures that exhibit all optically tunable properties, where the number of transparency windows can be tuned successively and switched to off-state. In this Letter, we theoretically investigate and demonstrate a dyn...
Preprint
Full-text available
Plasmon-induced-transparency (PIT) in nanostructures has been intensively investigated, however, no existing metasurface nanostructure exhibits all-optically tunable properties, where the number of transparency windows can be tuned successively, and switched to off-state. Here, we theoretically investigate and demonstrate dynamically tunable, multi...
Article
Full-text available
Heavy metal pollution in soil has severe impact on the human health and global environment. There is an urgent need for cost-effective devices capable of recognizing and detecting heavy metallic matters in soils. A broadband photoacoustic spectrometric (PAS) system was established for the detection of heavy metal contaminants in soil. The heavy met...
Article
In this paper, a two-path parallel scheme for m-QAM-OFDM transmission in optical wireless communications was proposed, and its principle was theoretically derived. This scheme transmitted two-path parallel OFDM signals, which carried m-QAM mapped data symbols and their conjugated data symbols respectively. Simple superimposition at the receiver was...
Preprint
Full-text available
Light passing through scattering media will be strongly scattered and diffused into complex speckle pattern, which however contains almost all the spatial information and color information of the objects. Although various technologies have been proposed to realize color imaging through the scattering media, current technologies are still complex wi...
Conference Paper
We developed a method to realize color imaging through the scattering media based on triple correlation technique. This method enables color imaging through the scattering media without the wavefront shaping technique and deconvolution technique.
Conference Paper
We propose a method to get the real depth information of the object based on the spatial coordinate transformation method in 3D polarization imaging. This technique is useful for 3D polarization imaging of single camera.
Conference Paper
Underwater imaging’s promising but challenging. This paper addresses a method to realize real-time underwater imaging by estimating DOP of backscatter automatically based upon polarization signatures of images. The results demonstrate the achievability of video processing.
Conference Paper
To solve depth information problem in 3D polarization imaging, we use monocular vision imaging model to get the actual depth of the object. Comparing to other methods, our method is more affordable and more convenient.
Conference Paper
The reflected light of small and dim target and backscattered light can be separated according to their sparsity and low-rank properties. The polarization azimuth images with the smallest light intensity are most suitable for separation.
Conference Paper
The degree of polarization of the target light in the underwater scene is accurately estimated based on the image correlation, by which the target light is recovered successful without loss of energy.
Conference Paper
This study focused on a polarization three-dimensional imaging technology under the natural scene. By solving the problem of diffuse reflection information missing, highlighted areas three-dimensional imaging is possible.
Article
Underwater imaging is attractive but challenging. Images could be severely degraded by the particles in turbid water because of backscatter generation and signal light attenuation. In this paper, we focus on the scheme of underwater imaging and study the methods of visibility enhancement of turbid underwater images based on polarimetric imaging uti...
Article
Optical imaging through scattering layers based on the ‘memory effect’ (ME) always suffers from a limited field of view. Here, we present a method that employs prior information to provide indispensable support for imaging behind a scattering medium, in which case the transversal distance between the targets is beyond the limited range determined b...
Article
Full-text available
Light passing through scattering media will be strongly scattered and diffused into complex speckle pattern, which contains almost all the spatial information and spectral information of the objects. Although various methods have been proposed to recover the spatial information of the hidden objects, it is still a challenge to simultaneously obtain...
Article
We hereby proposed and experimentally demonstrated an active polarization imaging technique, based on wavelength selection, for seeing through highly turbid water where targets are always visually lost. The method was realized by making use of the dependence of light scattering on wavelength in turbid water. Red light illumination was selected to m...
Preprint
Memory-effect-based methods have been demonstrated to be feasible to observe hidden objects through thin scattering layers, even from a single-shot speckle pattern. However, most of the existing methods are performed with narrowband illumination or require point light-sources adjacent to the hidden objects as the references, to make an invasive pre...
Article
In this paper, a novel OFDM symbol frame structure was proposed to improve the performance of underwater wireless optical communication (UWOC) systems with m-QAM-OFDM modulation. In the frame, the data-carrying OFDM symbol and corresponding phase-conjugated symbol was interleaved. At the receiver end, by simple superposition of received symbols, th...
Article
Photoacoustic imaging (PAI) has been widely investigated by researchers from a range of areas. According to the difference between excitation laser sources, PAI can be categorized into two main types, namely the time-domain and frequency-domain PAI. Although the frequency domain approach is more portable and economic than the other alternative, the...
Article
Full-text available
Optical imaging and focusing through complex samples is a challenge with important applications in many fields. The critical problem is that turbid media such as biological tissue and multimode optical fibers randomly scatter and diffuse light, preventing the formation of diffraction-limited focus and image. We demonstrate with numerical simulation...