Study of Sensitivity Enhancement and Dead Band Elimination in Laser Gyros

The essential elements that characterize the performance of a laser gyro are (a) a bidirectional ring laser, (b) a lightweight, efficient instrument (c) a high sensitivity to rotation and (d) a linear response without dead band. To address (c), substantial enhancement has been predicted through large intracavity (normal) dispersion dn/df. The objective of Phase I is to demonstrate experimentally this enhancement, in combination with demonstrating the absence of dead band (d) in a solid state laser. A key element is the realization that it is possible to engineer a mode-locked laser where the pulse envelope velocity is controlled by other parameters than the dispersion. We have demonstrated this property in a mode-locked laser with intracavity Fabry-Perot and with intracavity resonant atomic vapor. This property will be exploited in Phase I by inserting in a ring mode-locked Ti:sapphire laser a Fabry-Perot and a Rubidium cell, to demonstrate simultaneously the enhancement of the gyro sensitivity, the use of a solid state gain medium in a gyro, and the absence of dead band. In Phase II, these results will be implemented in a mode-locked fiber laser gyro, to demonstrate the light and efficient instrument required for space applications.