HeNe Parallel Plate Laser Development

Abstract

A parallel plate format is used for fabricating ' 'hard'' sealed HeNe lasers. The new packaging geometry and construction process are suitable for large scale manufacturing. Cut plate, molded plate, and folded beam lasers have been built and tested. Several changes from conventional lasers, such as evaporated film cathode and anode, square cross section bore, glass sealed Brewster windows, and "soft" glass bore materials, are discussed. The power output capability, measurements of gain and loss parameters, and the reliability of these lasers are also considered. IntroductionIn the early experimental designs of the HeNe laser [1,2], the emphasis was on obtaining operating models. As a result, geometrical considerations such as bore dimensions, straightness, and alignment were paramount concerns. Permanently sealed gas volumes, compact structures, long cathode lifetimes, rigid optical cavities, etc., soon became important as the need for commercial HeNe lasers developed. The emphasis shifted to ease of operation, reliability, long lifetime, and lower cost.

Cathodes for HeNe Lasers

“…Deposited film cathodes have many advantages in the fabrication of the parallel plate HeNe laser [12,13]. Electrical feed-throughs may be fabricated as extensions of the deposited cathode and subsequently isolated from the cathode chamber by seal glass.…”