Demonstration and investigation of pulsed injected locked solid-state laser oscillators with high frequency stability due to gain gratings without any active stabilization

本应用程序的目的是研究环路谐振器中通过增益光栅锁定的脉冲振荡器注入。这种方案的巨大优势在于其高精度频率稳定性的潜力，而不需要任何有源稳定电路或执行器，与最先进的频率稳定方案相比。将稳定的单片非平面环形振荡器作为种子激光器注入到高功率环路中。环形谐振腔镜之一是激光有源材料中的增益光栅，它的位置不固定，因此可以补偿谐振腔长度的波动。由于相干光束形成增益光栅的要求和增益光栅本身的布拉格选择性，环路振荡器可以很好地实现单频工作。频率锁定的环形振荡器发射脉冲与纳秒的持续时间，在mj范围内的能量与种子激光相同或几乎相同的频率与亚兆赫兹偏差的环形振荡器尚未被证明，这将是本应用的重点。回路的共振特性将被详细研究。无主动稳定的注入锁定脉冲固体激光振荡器将是许多物理和技术任务的重大进步，特别是在移动激光雷达应用中。这种方案可以推广到连续波注入锁定，也可以应用于激光源的相干组合。

The goal of this application is to investigate pulsed oscillators injection locked via gain gratings in loop resonators. The great advantage of such a scheme is its potential for high precision frequency stability without the need for any active stabilization circuit or actuator in contrast to state of the art frequency stabilization schemes. A stable monolithic non-planar ring oscillator will be used as seed laser that is injected into the high power loop. One of the loop resonator mirrors is a gain grating in the laser active material which is not fixed in position and thus can compensate for fluctuations of the resonator length. Single frequency operation can be realised very well in loop oscillators because of the coherence beam requirements to form the gain gratings and the Bragg selectivity of gain gratings themselves. A frequency locking of a loop oscillator emitting pulses with nanosecond duration, and energy in the mJ-range with identical frequencies or almost identical frequencies of the seed laser and loop oscillator with sub-MHz deviation was not demonstrated yet and will be in the focus of this application. The resonance behaviour of the loop will be investigated in detail. An injection locked pulsed solid state laser oscillator without active stabilization would be a major advance for many tasks in physics and technology especially for mobile lidar applications. In perspective such a scheme could be extended to continuous-wave-injection locking, or could be applied for coherent combination of laser sources.