This is an actual strip chart record showing the excellent single-frequency stability of a Lexel Model 85 Argon Laser with the Model 503 Temperature-Controlled Etalon Assembly. The laser output power was 300mW at 514.5nm. The frequency stability was measured using the iodiine absorption cell technique. After a 60-minute warmup, the maximum frequency excursion was less than ±75 MHz over the two-hour test period. The room temperature was maintained within 1°F using the normal building air conditioning system.

Each Lexel single-frequency ion laser is tested over a 10-hour period for similar performance.