Interference Optical Scanner.
Abstract
A 2-milliwatt He-Ne laser and beam-forming optics were used in a new light source. Solid state silicon photodiodes replaced the former photomultiplier tube. Two units, a two-channel amplitude comparator (to use the outputs from the interference channel and the normal channel to determine whether particles scanned are transparent or opaque, rejecting the latter) and a Pulse Height/Pulse Width discriminator (which sorts particles according to size and opacity) were fabricated. Nomarski prisms were abandoned as part of the detector system and some success with Wollaston prisms was had where lateral separation of beams occurred. Wollaston prisms produced a 1 deg divergence or recombining angle. A third, 0.6 deg Wollaston prism was added later to restore parallelism to the emerging light. The optical system of an operational interference optical scanner was studied. Optical interference can be used on a PACT system to render transparent organisms readily visible. More work is needed to perfect techniques and optical subassemblies for this last application. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1975
- Accession Number
- ADA029914
Entities
People
- A. H. Sarrafian
- C. B. Linnecke
- W. H. Hartung