High-power laser beam in higher-order Hermite–Gaussian modes

The sensitivities of current gravitational-wave detectors are limited around signal frequencies 100 Hz by mirror thermal noise. One proposed option to reduce this noise is operate the in a higher-order spatial laser mode. This operation would require high-power input beam such Here, we discuss generation Hermite–Gaussian modes HG2,2, HG3,3, and HG4,4 using one water-cooled light modulator (SLM) at continuous-wave optical power up 85 W. We report unprecedented conversion efficiencies for single SLM about 43%, 42%, 41%, respectively, demonstrate that robust against high power. an important step toward implementation future detectors.