 D. T. M. Davis, Jr.

D. T. M. Davis, Jr. coauthored the 1963 paper Rotation Rate Sensing with Traveling-wave Ring Lasers by W. M. Macek and D. T. M. Davis, Jr. with W. M. Macek. Its byline places both at Sperry Gyroscope Company. They reported rotation sensing with a continuously operating helium-neon laser in a square optical cavity, with counterpropagating beams combined at a detector.^[ref]

The measurement reads beating between optical fields. For two fields of frequencies $f_1,f_2$, a simple equal-amplitude model gives a detector term proportional toThe detector can therefore register the difference frequency without resolving either optical oscillation separately. In a ring laser gyroscope, the Sagnac effect makes that difference depend on angular velocity. This mathematical readout model explains why combining the two outputs matters; a pair of beam-power readings alone does not supply their frequency difference. The initial-only name above retains the verified publication identity.