laser俘获微观粒子的光学取向和自旋
Optical alignment and spinning of laser-trapped microscopic particles
摘要：
通过将角动量从光转移到材料，吸收微观粒子的光致旋转提高了光学驱动微机械的可能性。利用椭圆偏振激光束或具有螺旋相位结构的光束观察到了这种现象。但是，由于过热和不必要的轴向力，在这样的实验中很难开发高功率，将可实现的旋转速率限制在几赫兹。这个问题原则上可以通过使用透明粒子来克服，通过Beth在1936年首次观察到的机制来转移角动量，当时他报告了由于透射光的偏振变化而在石英波片中产生的微小扭矩。在这里，我们表明，光扭矩可以诱导微观双折射方解石颗粒举行的光镊。根据入射光束的偏振，粒子要么与偏振平面对齐（因此可以旋转指定的角度），要么以恒定的旋转频率旋转。由于这些微观粒子是透明的，它们可以在非常高的功率下保持在三维光阱中而无需加热。我们已经观察到超过350赫兹的旋转速率。
英文摘要：
Light-induced rotation of absorbing microscopic particles by transfer of angular momentum from light to the material raises the possibility of optically driven micromachines. The phenomenon has been observed using elliptically polarized laser beams or beams with helical phase structure. But it is difficult to develop high power in such experiments because of overheating and unwanted axial forces, limiting the achievable rotation rates to a few hertz. This problem can in principle be overcome by using transparent particles, transferring angular momentum by a mechanism first observed by Beth in 1936, when he reported a tiny torque developed in a quartz waveplate due to the change in polarization of transmitted light. Here we show that an optical torque can be induced on microscopic birefringent particles of calcite held by optical tweezers. Depending on the polarization of the incident beam, the particles either become aligned with the plane of polarization (and thus can be rotated through specified angles) or spin with constant rotation frequency. Because these microscopic particles are transparent, they can be held in three-dimensional optical traps at very high power without heating. We have observed rotation rates in excess of 350 Hz.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
