Photoelectricity in the micro-lens coating system has made progress

      Institute of Optoelectronic Technology, Institute of Optics and Electronics, Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Beijing 100083, China) The development of micro-lens antireflective film system has been improved by taking into account the incident angle and the thickness distribution of the microlenses on the microlens. The optical performance of the lens is significantly improved.

      Micro-lens is one of the most commonly used optical components in precision optical systems. Generally, in order to optimize the luminous flux and image quality, it is necessary to coat the antireflection coating on its surface. However, due to the special shape and size of the microlens, it is highly challenging to prepare an antireflective film with good optical performance on the microlens. The design of the antireflective film system determines the optical properties of the microlens. In order to optimize the micro-lens antireflective film system design, the micro-lens incident angle and film thickness distribution need to be fully considered. Existing commercial software in the implementation of anti-reflective film design can only consider the light incident angle, and can not take into account the film thickness distribution, and therefore can not achieve the best design of micro-lens coating system.

      In the case of a convex lens with a diameter of 10 mm and a radius of 10 mm, it is required to design an antireflection film with good optical performance consistency and a transmittance of 99.6% over the range of 480-720 nm. For the parallel beam irradiation, the incident angle distribution range of the convex lens is 0 to 30 °; the thickness uniformity of the film deposited on the microlens during the vacuum coating is about 86.2%. In the study of photoelectricity, three kinds of film design methods were compared, namely: D1, regardless of the incident angle and film thickness distribution on the microlens; D2, considering only the angle of incidence distribution, did not consider the film thickness distribution. The above two design methods are available in existing commercial software; D3, taking into account the incident angle and film thickness distribution on the microlenses. Based on these three design methods, the residual reflectance spectra at 480 nm to 720 nm are obtained at different vector height on the microlenses, as shown in the following figure. Corresponding to the design of D1, D2 and D3, the transmittance of the microlenses is better than 99.6%, and the proportion of the total aperture is 23%, 43.6% and 100%, respectively. This result proves the superiority of the design method of photoelectricity. The results were published on Chin. Opt. Lett.