A Study Of The Influencing Factors Of Optics-driven Bistability Of Optomechanics And Of ’Switching’ Effect Of Bistablility

The background of the bistable devices and its latest research progress was studied in this dissertation, and then a few kinds of actuations with its applications and limitations were described and compared in detail. As a result, the optical actuation was the choice for us to study the Fabry-Perot cavity system of optomechanics providing the driving force. We constructed a low finesse FP micro-optical cavity on the experimental platform of magnetic resonance force microscope (MRFM), and then the experimental measurement system was established. It was found that, the mechanical degrees of the micro-resonance cavity were coupled with the light field. When the intensity of the light field was strong enough, the bistability effect would be induced by the optomechanical coupling. We chose the optical actuation for attaining the state of bistablity of the cantilever accordingly. The intensity of the light field was adjusted to control the bistability of the optomechanical FP cavity, which provided a new all-optical actuation technique for majority of bistable devices. In addition, we only considered optical driven force and the elastic force of the cantilever, so that the essential characteristics of bistability effect were better embodied by the relatively simple system.We first studied the relationship between the intensity of the light field and the equilibrium position of the cantilever experimentally, and then we showed the factors influencing the bistablity effect of low finesse FP micro-optical cavity theoretically. The influencing factors we studied were laser powers and initial cavity detuning lengths. The experiments showed that the bistability effect was proportional to the increment of the laser power. The region of bistability was affected by the initial cavity detuning lengths with a role similar to translation. Furthermore, the results of simulation also confirmed the correctness of our experimental conclusions.The bistabilty effect made an impact on the cavity detuning lengths, and then the cavity detuning had sudden changes which were different with the increment/decrement of the laser power. The effect was analogous to the hysteresis loop. We also investigated the bistability leading to’switching’ effect. Experiments showed that the increment of the laser power strengthened the switching effect. In order to study the connection between the bandwidth of the cavity detuning and the laser power, we measured the variation trend of the bandwidth of the cavity detuning with the laser power increasing, and found that the bandwidth of the cavity detuning varied linearly with the laser power. When the laser power increased for1μW, the bandwidth of the cavity detuning increased for0.582. At last, we discussed the feasibility of such a switching effect device as an optomechnical switch.