An effective optical design method is proposed to solve the problem of adjustable view angle for infrared illuminator in active night vision systems. A novel total internal reflection (TIR) lens with three segments of the side surface is designed as the secondary optics of infrared emitting diode (IRED). It can provide three modes with different view angles to achieve a complete coverage of the monitored area. As an example, a novel TIR lens is designed for SONY FCB-EX 480CP camera. Optical performance of the novel TIR lens is investigated by both numerical simulation and experiments. The results demonstrate that it can meet the requirements of different irradiation distances quit well with view angles of 7.5°, 22° and 50°. The mean optical efficiency is improved from 62% to 75% and the mean irradiance uniformity is improved from 65% to 85% compared with the traditional structure.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.21.001113 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Expression profiling and characterization of key RGA involved in lentil Fusarium wilt Race 5 resistance.
World J Microbiol Biotechnol
September 2023
Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
Fusarium wilt is a major threat to lentil production in India and worldwide. The presence of evolving virulent races has imposed the necessity of reliable management practices including breeding for resistance using unexplored germplasms. The magnitude of resistance by the plant is determined by rapid recognition of the pathogen and induction of defence genes.
View Article and Find Full Text PDFResistance screening and characterization of cloned novel RGA from multi-race resistant lentil germplasm against Fusarium wilt ( f. sp. .
Front Plant Sci
April 2023
Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India.
Fusarium wilt caused by f. sp. () is the most devastating disease of lentil present worldwide.
View Article and Find Full Text PDFIn this paper, we designed a three-zone multifocus hybrid Fresnel lens concentrator without a homogenizer. This concentrator uses three types of prisms: a refractive prism, a single total internal reflection (STIR) prism, and a double TIR (DTIR) prism. In order to achieve a uniform irradiance distribution, the Fresnel lens is cut into four quadrants and reconnected.
View Article and Find Full Text PDFThe proposed total internal reflection (TIR)-based technique can be used for measuring the refractive index of lenses. Distribution of the phase difference between the - and -polarization states of the reflected light induced by TIR can be obtained by a polarization camera. The refractive index of the lens can be determined from the detected maximum phase difference, with the specific measurement equation.
View Article and Find Full Text PDFLens arrays are introduced to diminish the total internal reflection (TIR) that happens at chip-encapsulant and encapsulant-air interfaces of chip-on-board light-emitting diodes (COB-LEDs), so as to improve the light extraction efficiency (LEE) of the COB-LEDs. However, the LEE of COB-LEDs with lens array depends on the refractive index of the encapsulant layer and lens array , which was rarely concerned so far. Optical simulations based on a Monte Carlo ray tracing method, and experiments were conducted to investigate the effect of and on the LEE of COB-LEDs with millilens array.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!