Infrared/millimeter Wave Beam Combiner Utilizing Holographic Optical Element

The advantages of the common-aperture dual-mode operation for missile sensor has been identified for some time. An IR FPA offers unsurpassed !seeker resolution terminal guidance, while W-band radar has a wider field of view and longer-range target acquisition, even under adverse weather conditions. The same is true for airbome multiband sensors and other remote sensing applications. For instance, an IR/MMW imaging system can greatly improve aircraft landing capability and make possible all weather, dayhight operations even at airports and landing fields not equipped with modem navigation and landing aids. ’Ihe performance of a dual-mode common-aperture sensor is determined by the performance of each subsystem -the MMW radar and the IR FPA -and of the beam combiner. Figure 1 shows the function of the beam combining element in a dual mode simulator.