Fabrication of Binary Diffractive Lenses and the Application to LED Lighting for Controlling Luminosity Distribution

We designed and fabricated two types of binary diffractive lenses using Electron beam lithography (EBL) on optical films film for controlling LED light. In the case of the binary diffractive convex lens with 2-mm focal length, it is possible to control the luminous intensity distribution. To improve the diffraction efficiency and realize a thin LED light source, the binary diffractive lenses with 100-μm-order focal length are effective. Furthermore we fabricated and characterized the binary diffractive concave lenses for application in LED lighting. It is found that white-light LEDs are strongly diffused by using the binary diffractive concave lenses.

光子晶体发光二极管

利用光子晶体的光子禁带和光栅衍射效应可以提高LED的出光效率,扩大LED的应用范围。总结了光子晶体发光二极管的原理和典型器件。通过比较表明,与光子禁带效应相比,利用光栅衍射效应提高LED出光效率的方法更适用于电注入发光。因此可望用更廉价的方法在LED表面制造光子晶体,可通过光栅衍射效应来有效地提高其出光效率。

Optical design for an LED-based handheld underwater wireless optical communication system

We propose an LED reshaping lens design for a handheld underwater wireless optical system to solve the problem of targeting the receiver. The simulation results shows that the designed lens can achieve 0.91 light intensity uniformity and 91.39% optical efficiency in hemisphere space, even with the actual LED model. After fabrication with computer numeric control, the work demonstrates the design to be effective.

自集成透镜InGaAsP/InPDHLED及其离子束铣技术

本文报道在国内首次采用离子束铣技术研制自集成透镜InGaAsP/InP DH LED的实验结果。采用烘烤正性光致抗蚀剂来形成球状掩膜适合于离子束铣,且重复性很好。为了获得光洁的刻蚀表面,刻蚀条件均已最优化。

Optimized design of LED freeform lens for uniform circular illumination

An optimization method is proposed for designing an LED freeform lens which produces a uniform circular pattern with high energy efficiency.This method is composed of three main aspects:design of the initial guess,parameterization of the freeform surface,and construction of the merit function.The initial guess is created by solving an ordinary differential equation numerically.An approach of selecting optimization points is introduced for parameterization of the freeform surface.The merit function is constructed by use of the irradiance uniformity and the efficiency of the lens.Design examples are given,and the results show that the irradiance distribution is well controlled with a maximum uniformity(the relative standard deviation of irradiance,RSD) of 0.0122 and a maximum efficiency of 93.88%.This optimization method can be generalized to design freeform lenses with different lighting patterns or without rotational symmetry.

Coarse error analysis and correction of a two-dimensional triangulation range finder

A real-time two-dimensional （2D） triangulation range finder is presented, which is composed of two linear complementary metal oxidation semiconductor （CMOS） chips, two camera lenses, and four light emitting diodes （LEDs）. The high order distortion in image aberrations is the main factor responsible for the coarse errors. The theoretical prediction is in good agreement with experiments and the correction equation is used to obtain more reliable results with the unique distortion coefficient in tile whole working region.

基于积分球系统的有机-无机杂化钙钛矿发光二极管量子转化效率的测量

有机-无机杂化钙钛矿发光二极管(PeLED)作为一种新型发光器件,具有原料来源广、器件制备简单和载流子迁移率高等优点,使其成为显示与发光领域的研究热点之一。由于PeLED存在发光稳定性差和器件均匀发光区域小的缺点,并且对于PeLED量子效率的测试没有统一的测量方法。鉴于此,提出一种新型的PeLED量子转化效率测量系统。首先采用小尺寸积分球并结合光谱测量系统对PeLED发射光进行收集,最终得到其量子转化效率。然后采用GaN发光二极管的数据作为标准数据,并对该系统的中心波长、亮度及辐射亮度进行校准。最后使用该测量系统测量PeLED器件的性能。实验结果表明,当电压为3.2V时,PeLED的外量子效率最高,值为0.089%,与参考值的误差不超过6%。