Dual Thermoplastic Holography Recording System

Historically, holograms have been recorded on silver halide emulsions which require darkroom processing. In recent years, thermoplastic recording procedures have matured and commercial devices are now available. A thermoplastic device records the light intensity pattern in the hologram solely by using electromechanical forces and is an electronic device. The hologram is prepared for exposure, processed, and fixed electronically by a "dry" process, in place, within seconds. Recordings can be inspected immediately and data reduction initiated. In addition, poor recordings may be erased repeatedly until the desired hologram is produced. Since the plates are electronically activated, double plate holographic interferometry is implemented in-situ; as the rear plate is exposed before the front plate is sensitized. The plates are mounted in adjustable receptacles allowing for fringe control in holographic reconstruction. This paper describes the development and applications of a double plate thermoplastic holography device using a commercial single plate thermoplastic device.