The aircraft landing signal lamp is a kind of optical equipment which provides the pilot with visual landing optical indication. It is installed on the apron of the airport. The aircraft landing signal lamp is usually installed on the aircraft landing sign line. To ensure the safety of aircraft taking off and landing, the height of the lamp after installation should not exceed 30mm. Aircraft landing lights need to provide 360 degrees of horizontal direction, 7 degrees to 90 degrees of vertical direction, and the power should not be too large, therefore, the optical system is required to have a reasonable light distribution curve, high light utilization rate. Because pilots are equipped with night vision equipment at night, landing lights need to provide a near-infrared light signal as well as visible light. To make aircraft take off and land safer, this paper designs an optical system of aircraft landing signal light based on the principle of light guiding optics, which makes the upper surface of the lamp flush with the mounting surface. The height of the lamp after installation is 0mm. The optical system consists of LED integrated surface light source and light guiding glass column. Integrated surface light source integrates visible light LED chip and near infrared LED chip together. To make the light Angle larger and the light distribution curve more reasonable, the upper surface of the light guide glass column is in the form of microlens array. At the end of this paper, a photo of the optical indication effect of aircraft landing signal light is given.
The washing floodlight is a sort of optoelectronic equipment for the use on vessels which contain helipad, designed as a visual landing aid for the helicopter. Usually the washing floodlight is installed directly on the edge of deck, while the installation site should not be too high, normally lower than 350mm is recommended. In addition, since floodlight generally provides high and relative uniform illumination for a larger deck surface, it is necessary to have a reasonable light intensity distribution, high light intensity and high light energy efficiency. Meanwhile, the floodlight need to provide not only visible light but also infrared illumination to coordinate with night vision goggle. This paper provides a washing floodlight design with high light intensity and high average illumination. The illumination optical system consists of two separate portions, namely refraction and reflective illumination optical system. The refraction illumination optical system is a cylindrical lens with free-form surface, the upper part of lens is responsible for small angle illumination (about 0° to -5 ° in the vertical direction), while the nether part is responsible for large angle illumination (about -5 ° to -30 °in the vertical direction). Besides, the reflection illumination optical system is a cylindrical mirror with scaly conicoid reflection surfaces rather than traditional smooth quadric surface, which can improve the ability to control light, providing a larger angle of uniform illumination. In the later part of this paper, the illumination performance with 8 washing floodlight is simulated, and the illumination performance picture of a real washing floodlight is given.
Fly’s eye uniformizer is the key part of ArF lithography illumination system, whose main function is to illuminate the reticle uniformly. Due to the periodic structure of regular fly’s eye uniformizer and the high coherence of the ArF laser, the output intensity distribution is modulated with equidistant sharp intensity peaks (interference speckle pattern) which disturbed the uniformity on the reticle. In this paper, we design a chirped fly’s eye uniformizer which consists of chirped fly’s eye and a condenser for illumination system in ArF lithography system. The chirped fly’s eye consists of individually shaped micro-lenses defined by a parametric description which can be derived completely from analytical functions. The micro-lenses with different thicknesses in the chirped fly’s eye have a function of delaying the optical path which reducing the laser coherence and speckle pattern on the reticle. Detailed design process of the chirped fly’s eye uniformizer for numerical aperture (NA) 0.75 lithography illumination system is presented. Light intensity distribution on reticle produced by regular and chirped fly’s eye uniformizer are analyzed and compared by the method of wave optics, and the results show that chirped can restrain sharp intensity peaks efficiently. Furthermore, the chirped fly’s eye uniformizer has been traced in LightTools software under conventional and annual illumination modes, and the non-uniformity of the non-scan and scan direction on the reticle reached 0.75% and 1.24% respectively. The simulation results show that the chirped fly’s eye uniformizer can provide high illumination uniformity and reduce the speckle pattern efficiently without additional elements.
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