![](https://coimages.sciencemuseumgroup.org.uk/43/60/medium_thumbnail_1984_0663.jpg)
prototype HCN infra-red laser
- Made:
- 1970-1972 in Teddington and Hammersmith
The prototype commercial HCN gas laser unit consisting of a discharge tube and thermally stabilised optical system capable of giving 1 mW output in the far infra-red range, 1971.