Theoretical and experimental study on vibration sensitivity of cubic cavity for space applications

The increasing performance of ultra-stable lasers has made them attractive for non-laboratory and space field applications. How to reduce the vibration sensitivity of the optical reference cavity is one of the key points. To develop vibration-insensitive cavity for space applications, we investigate the vibration sensitivity of a cubic cavity with the length of 100 mm theoretically and experimentally. The functional expression of the fractional length change of the cubic cavity versus the cutting depth of the cubic spacer vertices and the compressive forces is presented for the first time. The vibration sensitivity of the 100 mm cubic cavity is measured as low as 2 x 10-11/g. Based on the vibration-insensitive cubic cavity, a 1 Hz-linewidth laser system with an envelope size of 450 mm x 541 mm x 598 mm is developed, which would be the prototype for space applications.