Today’s optical designs have overcome many of the problems that plagued early instrumentation, but reductions in size, weight, and power (SWaP) remain an ongoing goal. Now, researchers have developed a new imaging spectrometer with a significant reduction in SWaP while maintaining performance using innovative components.
The current state of the art of imaging spectrometers is really high-performing, but there are two types of improvements possible to make them better. You can make them optically faster by lowering the f-number, or you can make them smaller using innovative components so that the SWaP penalty is not as large.
The team focused on the latter improvement. They employed two innovative components: a catadioptric lens and a flat dual-blaze immersion grating. The catadioptric lens—a concave meniscus lens with a reflective coating on the back—combines reflective and refractive elements into a single and more compact component. It also uses a flat grating rather than a convex or concave one, which is much easier to manufacture in addition to saving space.