Phase-Lock Control Considerations for Multiple, Coherently Combined Lasers.
Abstract
This paper presents design considerations and fundamental performance limitations of phase-lock control loops used to coherently combine an array of lasers. A two-laser control loop designed to lock the differential frequency/phase between two lasers to a specified reference is first investigated. An integro-differential equation, valid for the linearized operating region of the loop, is derived in terms of the specified (desired) phase control, the phase measurement (heterodyne) noise, and the laser phase noise (instabilities). Solution of the equation results in an expression for the lasers' phase error variance in terms of the closed-loop noise equivalent bandwidth, the 100 measurement noise, and the lasers' field linewidths. Loop acquisition time, frequency pull-in range, and steady state phase error are also examined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1977
- Accession Number
- ADA052915
Entities
People
- James Burton Armor Jr
Organizations
- Air Force Institute of Technology