MSc thesis: Fiber-based laser stabilization for gravitational-wave detectors

Stellenangebot vom 23. Januar 2023

Current and future ground-based gravitational-wave detectors (GWDs) require high power and the lowest noise from their laser sources. These requirements can be best fulfilled by fiber amplifiers that amplify the laser beam guided in an optical fiber by stimulated emission of ions integrated into the fibers.

In current laser systems for ground-based GWDs, the laser power and frequency are sensed and pre- stabilized in-air (after decoupling from the fiber). These in-air optics add complexity and noise coupling paths, like laser beam pointing noise.

Here we want to test the integration of laser power (and frequency) sensors already into the optical fiber assembly to enable low noise sensing, the fastest feedback control loops, and highly integrated optical setups. These developments could make the currently used free-space laser pre-stabilization systems for GWDs’ laser systems obsolete by replacing several square meters of optics with a much less space consuming fiber assembly, which can directly connect to the main vacuum system of a GWD.

Your tasks

Setup of a lab experiment with currently used free beam sensors.
Mechanical and electric design of optical fiber-based, low noise laser power (and laser frequency) sensors.
Test, optimization, and comparison of fiber-based laser noise sensing vs. free beam sensing with novel characterization schemes like quantum correlation measurement (see ref. below).

(Approximate work division: 30 % laser lab work / 40 % assembly and test of electric circuits and mechanics / 30 % computer design, simulation, and data evaluation with, e.g., Inventor, Eagle, MATLAB/Python, Gnuplot, and computer-controlled lab experiments)