Programmable microshutter arrays for the JWST NIRSpec

A programmable transmissive field selector for the James Webb space telescope (JWST) near-infrared spectrometer (NIRSpec) is being developed. A primary goal for JWST is to detect the first galaxies to form in the universe, and then to follow their evolution and the growth of structure. Large scale redshift surveys are essential tools to allow researchers to identify these first galaxies, and to follow the subsequent development of structure. High redshift galaxy candidates will be sparse on the sky even with JWST, so a multi-object is essential to provide the most capable tool for this study of the early universe. Using micro electrical mechanical systems (MEMS) techniques, transmissive microshutter arrays are produced which permit opening of shutter elements under random access control. With this device, images of the sky can be used to identify objects of interest, and can then program the open areas in the telescope focal plane to allow the light from these candidate objects to enter the spectrograph. The programmable field selector, which is used to accept the light from the candidate objects, is one of the most challenging components in a multi-object spectrograph.