半主动激光探测制导和红外成像制导结合使用能够获得主被动探测模式,提升导引头的全天候探测能力、抗干扰能力和目标捕获跟踪能力。激光红外复合制导导引头中光学系统的性能直接影响制导武器系统的探测距离、目标识别和命中精度。若复合导引头采用分离孔径式光学系统,每一个通道采用单独的光学结构和探测器,较容易实现,但会带来空间配准等方面的问题,并且系统体积和质量较大。文中采用共孔径光学结构,考虑激光(1.064 μm)和红外(8~12 μm)光谱波段的透过率,通过焦距匹配方法共用整流罩和一片高透过率透镜完成复合光学设计。激光信号通过整流罩和第一片透镜聚焦,被位于孔径中心的平面反射镜反射到镜筒侧面,由四象限探测器接收。红外光信号经孔径外围通过,由包含衍射透镜的三片透镜成像到非制冷焦平面探测器上。整个光学系统经过-45~60 ℃无热化设计,光学系统整体结构简单紧凑、体积小,总长小于86 mm,口径小于62 mm。此光学系统设计可以应用于激光红外复合制导火箭弹、导弹等武器平台,为高效费比的高技术战争提供技术储备。

The combination of semi-active laser detection guidance and infrared imaging guidance can obtain active and passive detection modes, improving the seeker’s all-weather detection ability, anti-interference ability and target capture tracking ability. The performance of the optical system in the laser infrared composite guidance seekers directly determines the detection range, target recognition and hit accuracy of the guided weapon system. The composite seeker adopts a separate aperture optical system, and each channel adopts a separate optical structure and detector, which is easier to achieve, but it will bring problems such as spatial registration, and the system volume and mass are large. In this paper, a common aperture optical structure is adopted, and the transmittance of laser (1.064 μm) and infrared (8~12 μm) spectral bands is considered, and the composite optical design is achieved by using a focal length matching method to share a fairing and a high transmittance lens. The laser signal is focused through the fairing and the first lens, which is then reflected to the side of the lens barrel by a planar mirror located in the center of the aperture, which is received by a four-quadrant detector. The infrared light signal passes through the periphery of the aperture and is imaged onto an uncooled focal plane detector by three lenses containing diffractive lenses. The whole optical system through -45~60 ℃ no heating design, the overall structure of the optical system is simple and compact, small size, the total length is less than 86 mm, the caliber is less than 62 mm. The optical system design can be applied to laser infrared composite guided rockets, missiles and other weapon platforms, providing technical reserves for high-tech warfare with high efficiency and cost.