White-light System Research Articles

Multi-Gbit/s phosphor-based white-light and blue-filter-free visible light communication and lighting system with practical transmission distance.

High speed visible light communication (VLC) is a technology with great potential for future mobile and wireless communication. Here, we report and demonstrate a 2.705 Gbit/s white-light VLC and illumination system supporting indoor transmission distance of 1.5 m, corresponding a illumination of 545 lux. We also study the performance tolerance offset ranges in both x- and y-directions.

Technical note: The use of 3D printing in dental anthropology collections.

Rapid prototyping (RP) technology is becoming more affordable, faster, and is now capable of building models with a high resolution and accuracy. Due to technological limitations, 3D printing in biological anthropology has been mostly limited to museum displays and forensic reconstructions. In this study, we compared the accuracy of different 3D printers to establish whether RP can be used effectively to reproduce anthropological dental collections, potentially replacing access to oftentimes fragile and irreplaceable original material. We digitized specimens from the Yuendumu collection of Australian Aboriginal dental casts using a high-resolution white-light scanning system and reproduced them using four different 3D printing technologies: stereolithography (SLA); fused deposition modeling (FDM); binder-jetting; and material-jetting. We compared the deviations between the original 3D surface models with 3D print scans using color maps generated from a 3D metric deviation analysis. The 3D printed models reproduced both the detail and discrete morphology of the scanned dental casts. The results of the metric deviation analysis demonstrate that all 3D print models were accurate, with only a few small areas of high deviations. The material-jetting and SLA printers were found to perform better than the other two printing machines. The quality of current commercial 3D printers has reached a good level of accuracy and detail reproduction. However, the costs and printing times limit its application to produce large sample numbers for use in most anthropological studies. Nonetheless, RP offers a viable option to preserve numerically constraint fragile skeletal and dental material in paleoanthropological collections.

High-Bandwidth White-Light System Combining a Micro-LED with Perovskite Quantum Dots for Visible Light Communication.

This work proposes a high-bandwidth white-light system consisting of a blue gallium nitride (GaN) micro-LED (μLED) exciting yellow-emitting CsPbBr1.8I1.2 perovskite quantum dots (YQDs) for high-speed real-time visible light communication (VLC). The packaged 80 μm × 80 μm blue-emitting μLED has a modulation bandwidth of ∼160 MHz and a peak emission wavelength of ∼445 nm. The achievable bandwidth of the white-light system is up to 85 MHz in the absence of filters and equalization technology. Meanwhile, the bandwidth of the YQDs as a color converter is as high as 73 MHz with the blue GaN μLED as the pump source. A maximum data rate of 300 Mbps can be achieved by taking advantage of the high bandwidth of the white-light system using the non-return-to-zero on-off keying (NRZ-OOK) modulation scheme. The resultant bit-error rate is 2.0 × 10-3, well beneath the forward error correction criterion of 3.8 × 10-3 required for error-free data transmission. In addition, the YQDs which we proposed as a color converter possess high stability for VLC. After half a year, the achievable bandwidths of the white-light system and the YQDs are still up to 83 and 70 MHz, respectively. This study provides the direction of developing high-bandwidth white-light system for both high-efficiency solid-state lighting and high-speed VLC.

红外/白光混合补光系统在智能交通中的应用研究

红外/白光混合补光系统在智能交通中的应用研究

Near-infrared Intraoperative Imaging of Thoracic Sympathetic Nerves: From Preclinical Study to Clinical Trial.

The sympathetic nervous system controls and regulates the activities of the heart and other organs. Sympathetic nervous system dysfunction leads to disease. Therefore, intraoperative real-time imaging of thoracic sympathetic nerves (ITSN) would be of great clinical significance for diagnosis and therapy. The aim of this experimental study was to evaluate the feasibility and validity of intraoperative ITSN using indocyanine green (ICG).Methods: ITSN using ICG was performed on 10 rabbits to determine its feasibility. Animals were allocated to two groups. The rabbits in one group received the same dose of ICG, but were observed at different times. The rabbits in the other group were administered different doses of ICG, but were observed at the same time. Signal to background ratio (SBR) was measured in regions of interest in all rabbits. Furthermore, fifteen consecutive patients with pulmonary nodules were intravenously injected with ICG 24 h preoperatively and underwent near-infrared (NIR) fluorescence imaging (FI) thoracoscopic surgeries between July 2015 and June 2016. A novel self-developed NIR and white-light dual-channel thoracoscope system was used. SBRs of thoracic sympathetic nerves were calculated in all patients.Results: In the preclinical study, we were able to precisely recognize each rabbit's second (T2) to fifth (T5) thoracic ganglia on both sides of the spine using ITSN with ICG. In addition, we explored the relationship between SBR and the injection time of ICG and that between SBR and the dose of ICG. Using the novel dual-channel thoracoscope system, we were able to locate the ganglia from the stellate ganglion (SG) to the sixth thoracic ganglion (T6), as well as the chains between these ganglia in all patients with a high SBR value of 3.26 (standard deviation: 0.57). The pathological results confirmed our findings.Conclusion: We were able to use ICG FI to distinguish thoracic sympathetic nerves during NIR thoracoscopic surgery. The technique may replace the rib-oriented method as standard practice for mapping the thoracic sympathetic nerves.

Development and application of the near-infrared and white-light thoracoscope system for minimally invasive lung cancer surgery.

In minimally invasive surgery, the white-light thoracoscope as a standard imaging tool is facing challenges of the low contrast between important anatomical or pathological regions and surrounding tissues. Recently, the near-infrared (NIR) fluorescence imaging shows superior advantages over the conventional white-light observation, which inspires researchers to develop imaging systems to improve overall outcomes of endoscopic imaging. We developed an NIR and white-light dual-channel thoracoscope system, which achieved high-fluorescent signal acquisition efficiency and the simultaneously optimal visualization of the NIR and color dual-channel signals. The system was designed to have fast and accurate image registration and high signal-to-background ratio by optimizing both software algorithms and optical hardware components for better performance in the NIR spectrum band. The system evaluation demonstrated that the minimally detectable concentration of indocyanine green (ICG) was 0.01 ?? ? M , and the spatial resolution was 35 ?? ? m . The in vivo feasibility of our system was verified by the preclinical experiments using six porcine models with the intravenous injection of ICG. Furthermore, the system was successfully applied for guiding the minimally invasive segmentectomy in three lung cancer patients, which revealed that our system held great promise for the clinical translation in lung cancer surgeries.

Self-gauged fiber-optic micro-heater with an operation temperature above 1000°C

We report a fiber-optic micro-heater based on a miniature crystalline silicon Fabry-Perot interferometer (FPI) fusion spliced to the endface of a single-mode fiber. The silicon FPI, having a diameter of 100 μm and a length of 10 or 200 μm, is heated by a 980 nm laser diode guided through the lead-in fiber, leading to a localized hot spot with a temperature that can be conveniently tuned from the ambient temperature to >1000°C in air. In the meantime, using a white light system operating in the 1550 nm wavelength window where the silicon is transparent, the silicon FPI itself also serves as a thermometer with high resolution and high speed for convenient monitoring and precise control of the heater temperature. Due to its small size, high temperature capability, and easy operation, the micro-heater is attractive for applications in a variety of fields, such as biology, microfluidics system, mechanical engineering, and high-temperature optical sensing. As an example, the application of this micro-heater as a micro-boiler and micro-bubble generator has been demonstrated.

Adaptive filtering for white-light LED visible light communication

White-light phosphor-based light-emitting diode (LED) can be used to provide lighting and visible light communication (VLC) simultaneously. However, the long relaxation time of phosphor can reduce the modulation bandwidth and limit the VLC data rate. Recent VLC works focus on improving the LED modulation bandwidths. Here, we propose and demonstrate the use of adaptive Volterra filtering (AVF) to increase the data rate of a white-light LED VLC system. The detailed algorithm and implementation of the AVF for the VLC system have been discussed. Using our proposed electrical frontend circuit and the proposed AVF, a significant data rate enhancement to 700.68 Mbit / s is achieved after 1-m free-space transmission using a single white-light phosphor-based LED.

Low cost, high performance white-light fiber-optic hydrophone system with a trackable working point.

A working-point trackable fiber-optic hydrophone with high acoustic resolution is proposed and experimentally demonstrated. The sensor is based on a polydimethylsiloxane (PDMS) cavity molded at the end of a single-mode fiber, acting as a low-finesse Fabry-Perot (FP) interferometer. The working point tracking is achieved by using a low cost white-light interferometric system with a simple tunable FP filter. By real-time adjusting the optical path difference of the FP filter, the sensor working point can be kept at its highest sensitivity point. This helps address the sensor working point drift due to hydrostatic pressure, water absorption, and/or temperature changes. It is demonstrated that the sensor system has a high resolution with a minimum detectable acoustic pressure of 148 Pa and superior stability compared to a system using a tunable laser.

Ultra-Fast SiC Wafer Surface Roughness Mapping

SiC wafer surface roughness is known to affect the electrical properties of certain power devices. As a result, inspection of the surface roughness can be a very important step for SiC device manufacturing processes. In this paper, we propose a newly fast surface roughness measurement method using Differential Interference Contrast (DIC) microscopy image. Results from this method were compared against white-light interference measurement system and a good correlation was confirmed. The comparison result confirmed that this method was a valid method to measure the surface roughness. This method enables users to inspect the surface roughness in 5 minutes (100mm wafer) and 10 minutes (150mm wafers), respectively.

212 White light imaging vs Storz Professional Image Enhancement System (SPIES) cystoscopy during follow up of patients submitted to WLI-transurethral resection of non-muscle-invasive bladder cancer: Preliminary results of a bicenter randomized diagnostic trial

212 White light imaging vs Storz Professional Image Enhancement System (SPIES) cystoscopy during follow up of patients submitted to WLI-transurethral resection of non-muscle-invasive bladder cancer: Preliminary results of a bicenter randomized diagnostic trial

Simple method for simultaneously measuring the magnitude and direction of 2D in-plane displacement in white-light speckle photography

A simple method for simultaneously measuring the magnitude and direction (or argument) of a 2D in-plane displacement vector is presented. The theoretical mechanism for extracting the desired displacement signal from random noises produced by the nonoverlapping area of the recorded specklegrams of the test specimen surface is derived in detail. This procedure is realized by establishing a 1D displacement model in a white-light speckle photographic system using discrete Fourier transform shifting theorem. Results of the computer simulation and experiment show that the present method exhibits advantages such as convenient displacement direction determination, better robustness and wider measurement range than those of the traditional fringe analysis-based method. These characteristics make the proposed method a potential approach in practical applications.

Clinical Experiences of NBI Laryngoscope in Diagnosis of Laryngeal Lesions

Objectives: (1) Describe the use of narrowband imaging (NBI) to enhance diagnostic sensitivity and accuracy in an impressive number of patients. (2) Develop a complete description list of each laryngeal condition, which can serve as a criteria for further laryngoscopic examinations and diagnosis. Methods: This study was conducted between January 2012 and October 2013 at the Department of Otolaryngology, the second hospital attached to Jilin University (Changchun Jilin, China). A total of 3675 patients (2092 males, 1583 females; mean age 50.2 ± 19.5 years) were enrolled in this study. All 3675 patients underwent laryngoscopy equipped with conventional white light and NBI system. A total of 1153 lesions were classified into different groups according to their histopathological results. Results: On NBI view, mucosa of a normal vocal fold was light brown. Intraepithelial vessels displayed blue-green, which were in striking contrast to the surrounding mucosa. Polyps demonstrated a color of light green. Cysts and mucocele appeared as light white. Leukoplakia was shown as a white color and hyperplastic epithelial lesions appeared as a slightly brownish color. Erythroplakia appeared as well-distributed dark brown lesions. Pachydermia displayed light white with a quite different shape from that of cysts. Papilloma were shown as quite delicate green. Abnormal submucosal microvessel changes visualized in laryngeal carcinoma lesions were shown as typical scattered dark brownish spots. Sensitivity and specificity for the diagnosis of malignancy by means of NBI view calculated from these results were 98.81 and 99.89%, respectively. Conclusions: The advent of NBI is a breakthrough in the field of assessing laryngeal diseases, especially malignant ones.

Automated mosaicing of feature-poor optical coherence tomography volumes with an integrated white light imaging system.

We demonstrate the first automated, volumetric mosaicing algorithm for optical coherence tomography (OCT) that both accommodates 6-degree-of-freedom rigid transformations and implements a bundle adjustment step amenable to generating large fields of view with endoscopic and freehand imaging systems. Our mosaicing algorithm exploits the known, rigid connection between a combined white light and OCT imaging system to reduce the computational complexity of traditional volumetric mosaicing pipelines. Specifically, the search for 3-D point correspondences is replaced by two, 2-D processing steps: We first coregister a pair of white light images in 2-D and then generate a surface map based on the volumetric OCT data, which is used to convert 2-D image homographies into 3-D volumetric transformations. A significant benefit of our dual-modality approach is its tolerance for feature-poor datasets such as bladder tissue; in contrast, approaches to mosaic feature-rich volumes with significant variations in the local intensity gradient (e.g., retinal data containing prolific vasculature) are not suitable for such feature-poor datasets. We demonstrate the performance of our algorithm using ex vivo bladder tissue and a custom tissue-mimicking phantom. The algorithm shows excellent performance over the range of volume-to-volume transformations expected during endoscopic examination and comparable accuracy with several orders of magnitude superior run times than an open-source gold-standard algorithm (N-SIFT). We anticipate the proposed algorithm can benefit bladder surveillance and surgical planning. Furthermore, its generality gives it broad applicability and potential to extend the use of OCT to clinical applications relevant to large organs typically imaged with freehand, forward-viewing endoscopes.

OBSERVATIONS OF LINEAR POLARIZATION IN A SOLAR CORONAL LOOP PROMINENCE SYSTEM OBSERVED NEAR 6173 Å

White-light observations by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager of a loop-prominence system occurring in the aftermath of an X-class flare on 2013 May 13 near the eastern solar limb show a linearly polarized component, reaching up to $\sim$20% at an altitude of $\sim$33 Mm, about the maximal amount expected if the emission were due solely to Thomson scattering of photospheric light by the coronal material. The mass associated with the polarized component was 8.2$\times$10$^{14}$ g. At 15 Mm altitude, the brightest part of the loop was 3(+/-0.5)% linearly polarized, only about 20% of that expected from pure Thomson scattering, indicating the presence of an additional unpolarized component at wavelengths near Fe I (617.33 nm), probably thermal emission. We estimated the free electron density of the white-light loop system to possibly be as high as 1.8$\times$10$^{12}$ cm$^{-3}$.

Simple digital FIR equalizer design for improving the phosphor LED modulation bandwidth in visible light communication

We propose and demonstrate a simple digital post-equalization technique to improve the bandwidth-limitation of light-emitting-diode (LED) visible-light-communication (VLC) channel. The design of finite-impulse-response equalizer according to the channel response is presented to improve the bandwidth limitation of LED VLC channel. Here, no optical blue filter is used. The simulation and experimental results show \(\sim \)10 times enhancement of the direct modulation speed of white-light LED VLC system. When compares with the previous demonstration using high-pass equalization circuit constructed by lumped capacitor and resistor, the proposed scheme shows an improvement in signal quality and transmission distance, and a 10 Mbit/s error-free free-space transmission over 1 m can be achieved under the bit error rate of \(< 10^{-9}\).

654 Quantitative Targeted Wide Area In Vivo Imaging of Neoplasia in Barrett's Esophagus

Introduction and aim: Colonoscopy is considered to be the most sensitive tool to detect colorectal neoplasms, including small and flat lesions. Nevertheless, detection of such lesions is still incomplete, giving rise to interval cancers, particularly in patients with Lynch syndrome and other hereditary disorders. To improve the detection of (pre)malignant lesions nearinfrared endoscopy, guided bymolecular targeted fluorescent tracers, may hold great promise. Therefore, we developed a combined white-light and near-infrared (WLNI) endoscopic system, as well as two clinically approved fluorescent labeled antibodies, targeting vascular endothelial growth factor-A (VEGF-A) and epithelial growth factor receptor (EGFR). In the present study we investigated VEGF-A and EGFR expression in adenomas and CRC of Lynch patients, as potential targets for (pre)malignant detection. Subsequently we validated the newly developed WLNI endoscopic system, together with intravenously injected fluorescent anti-VEGF-A and anti-EGFR antibodies, in human CRC mouse models. Materials and Methods: VEGF-A and EGFR expression was analyzed by immunohistochemical staining of 34 CRC, 64 high-grade dysplastic (HGD) adenomas, and adjacent normal colon crypts of Lynch patients. The endoscopic system consisted of a custom made clinically approved WLNI camera, comprising a color camera and an ultra-sensitive camera for concurrent white-light and NIR fluorescence acquisition, attached to either a clinical fiberscope or a multi-modal fiber-optic bundle. The WLNI system was evaluated in vivo in CRC subcutaneous (sc) and intraperitoneal (ip) mouse models of bioluminescent CRC cell lines (HCT116-luc, HT29luc2), using bevacizumab-800CW (anti-VEGF-A) and cetuximab-800CW (anti-EGFR). Results: VEGF-A and EGFR were significantly overexpressed in 95% and 74% of HGD adenomas and in 100% and 85% of CRC, compared to adjacent normal crypts (resp. P,0.001/P,0.05 and P,0.05/P,0.001). Tumor-to-background ratio was high (3.2±0.9 for bevacizumab-800CW and 5.7±2.9 for cetuximab-800CW in the HCT116-luc sc model). WLNI endoscopy demonstrated excellent instant visualization of the sc and ip tumors (diameter ≥1 mm), with clear tumor boundaries and a low background fluorescence, demonstrating very high sensitivity and specificity of our WLNI endoscopic system. Conclusion: VEGF-A and EGFR are attractive targets for molecular targeted fluorescence endoscopy in Lynch patients based on their expression patterns. The newly developed WLNI endoscopic system using clinically approved molecular targeted fluorescent antibodies, enables instant visualization of very small tumor lesions in CRC mice models, with an excellent sensitivity and specificity. These results support clinical evaluation of WLNI endoscopy, in order to enhance early detection of colorectal (pre)malignancies and improve potentially outcome in patients.

653 Towards Instant Detection of (Pre)Malignant Lesions by Ultrasensitive Near-Infrared Fluorescence Endoscopy, Using Molecular Targeted Fluorescent Antibodies

Introduction and aim: Colonoscopy is considered to be the most sensitive tool to detect colorectal neoplasms, including small and flat lesions. Nevertheless, detection of such lesions is still incomplete, giving rise to interval cancers, particularly in patients with Lynch syndrome and other hereditary disorders. To improve the detection of (pre)malignant lesions nearinfrared endoscopy, guided bymolecular targeted fluorescent tracers, may hold great promise. Therefore, we developed a combined white-light and near-infrared (WLNI) endoscopic system, as well as two clinically approved fluorescent labeled antibodies, targeting vascular endothelial growth factor-A (VEGF-A) and epithelial growth factor receptor (EGFR). In the present study we investigated VEGF-A and EGFR expression in adenomas and CRC of Lynch patients, as potential targets for (pre)malignant detection. Subsequently we validated the newly developed WLNI endoscopic system, together with intravenously injected fluorescent anti-VEGF-A and anti-EGFR antibodies, in human CRC mouse models. Materials and Methods: VEGF-A and EGFR expression was analyzed by immunohistochemical staining of 34 CRC, 64 high-grade dysplastic (HGD) adenomas, and adjacent normal colon crypts of Lynch patients. The endoscopic system consisted of a custom made clinically approved WLNI camera, comprising a color camera and an ultra-sensitive camera for concurrent white-light and NIR fluorescence acquisition, attached to either a clinical fiberscope or a multi-modal fiber-optic bundle. The WLNI system was evaluated in vivo in CRC subcutaneous (sc) and intraperitoneal (ip) mouse models of bioluminescent CRC cell lines (HCT116-luc, HT29luc2), using bevacizumab-800CW (anti-VEGF-A) and cetuximab-800CW (anti-EGFR). Results: VEGF-A and EGFR were significantly overexpressed in 95% and 74% of HGD adenomas and in 100% and 85% of CRC, compared to adjacent normal crypts (resp. P,0.001/P,0.05 and P,0.05/P,0.001). Tumor-to-background ratio was high (3.2±0.9 for bevacizumab-800CW and 5.7±2.9 for cetuximab-800CW in the HCT116-luc sc model). WLNI endoscopy demonstrated excellent instant visualization of the sc and ip tumors (diameter ≥1 mm), with clear tumor boundaries and a low background fluorescence, demonstrating very high sensitivity and specificity of our WLNI endoscopic system. Conclusion: VEGF-A and EGFR are attractive targets for molecular targeted fluorescence endoscopy in Lynch patients based on their expression patterns. The newly developed WLNI endoscopic system using clinically approved molecular targeted fluorescent antibodies, enables instant visualization of very small tumor lesions in CRC mice models, with an excellent sensitivity and specificity. These results support clinical evaluation of WLNI endoscopy, in order to enhance early detection of colorectal (pre)malignancies and improve potentially outcome in patients.

Fiber-Based White-Light Interferometry for Nanoscale Distance Measurement and Control

We present a fiber-based white-light interferometry system capable of nanoscale distance measurement and control. Our prototype contains two cleaved single mode fibers tightly clamped together. Using a supercontinuum white-light source, we can achieve distance control with a standard deviation of <; 4 nm. This method is potentially suitable for applications that require noncontact measurements or that involve highly deformable structures.

Non-Contact Measurement for 3D Profile of Hybrid Metal Thin Film by White-Light Interference System

Non-Contact Measurement for 3D Profile of Hybrid Metal Thin Film by White-Light Interference System