LabVIEW-based laser frequency stabilization system with phase-sensitive detection servo loop for Doppler LIDAR applications

Abstract

Resonance fluorescence Doppler lidars using Doppler shift and spectral broadening effects are the principal instruments to simultaneously measure wind and temperature in the middle atmosphere. Such lidars demand high accuracy, precision, and stability of the laser optical frequency. Current resonance Doppler lidars suffer various problems in frequency stabilization that limit their locking precision and stability. We have addressed these problems by developing a LabVIEW®-based laser frequency locking system. This new system utilizes wavelengthmodulation and phase-sensitive-detection techniques in conjunction with a proportional-integral-derivative feedback servo loop. It achieves better than ±1-MHz locking precision and stability over 1 h. The system also remains locked throughout a series of abrupt disturbance tests. Owing to its high locking precision, immunity to electronic and laser noise, reliability, and flexibility in adapting for various systems, we believe that this new system represents a marked improvement in resonance Doppler lidar technology. ©

Ultra-sensitive single-beam atom-optical magnetometer using weak measurement method

“…1 without the SBC), the state-of-polarization of the onresonance light beam (λ = 780nm) from the diode laser (Vantage 7100, NewFocus) entering the atomic medium (Rb) is kept fixed at 0.785 rad (45 o ) with respect to x using the polarizer P. The Rubidium cell is 7 cm long and 2.5 cm diameter and is placed on-axis within the solenoid coils surrounded by a 3-layer µ-metal shield and known longitudinal magnetic field is applied by passing current from a stabilized current source (Keithley 6221). The frequency of the laser is stabilized using saturation absorption spectroscopy [17] to be at the D2 transition of Rb 85 atoms. The laser beam is nearly coolimated with a power of 1mW over a beam diameter of 0.4cm, corresponding to beam intensity of 8mW/cm 2 at the vapour cell.…”

Simple locking of infrared and ultraviolet diode lasers to a visible laser using a LabVIEW proportional-integral-derivative controller on a Fabry-Perot signal

“…There are many techniques of varying difficulties to lock lasers, such as optical feedback locking 3 , Doppler-free spectroscopy 4,5 , locking to a stabilized reference laser in a transfer cavity [6][7][8][9][10][11][12] , and locking to ion transitions via a hollow cathode lamp 13,14 . These methods, while effective, each present their own unique challenges to implement.…”

A scalable, self-analyzing digital locking system for use on quantum optics experiments

“…Mostly, however, the advantage of digital locking over analog systems lies in its flexibility: the ability to change the functionality of the system by altering the control code rather than having to purchase new equipment or physically modify old equipment. This makes a digital system easily reproducible, as well as having the ability to add complex logic which would be difficult to include with analog circuits alone (for examples see Ref.s [3] and [4]). Using the added power of digital control has lead many to develop novel methods for frequency stabilizing lasers (for example see Ref.s [5][6][7][8][9][10]).…”