Hoffmann Maximilian, Papadopoulos Ioannis N, Judkewitz Benjamin
Opt Lett. 2018 Jan 1;43(1):22-25. doi: 10.1364/OL.43.000022.
The controlled modulation of an optical wavefront is required for aberration correction, digital phase conjugation, or patterned photostimulation. For most of these applications, it is desirable to control the wavefront modulation at the highest rates possible. The digital micromirror device (DMD) presents a cost-effective solution to achieve high-speed modulation and often exceeds the speed of the more conventional liquid crystal spatial light modulator but is inherently an amplitude modulator. Furthermore, spatial dispersion caused by DMD diffraction complicates its use with pulsed laser sources, such as those used in nonlinear microscopy. Here we introduce a DMD-based optical design that overcomes these limitations and achieves dispersion-free high-speed binary phase modulation. We show that this phase modulation can be used to switch through binary phase patterns at the rate of 20 kHz in two-photon excitation fluorescence applications.
为了进行像差校正、数字相位共轭或图案化光刺激，需要对光波前进行可控调制。对于大多数此类应用，希望尽可能以最高速率控制波前调制。数字微镜器件（DMD）提供了一种经济高效的解决方案来实现高速调制，其速度通常超过更传统的液晶空间光调制器，但本质上是一种幅度调制器。此外，由DMD衍射引起的空间色散使其与脉冲激光源（如非线性显微镜中使用的那些）的使用变得复杂。在这里，我们介绍一种基于DMD的光学设计，该设计克服了这些限制并实现了无色散高速二元相位调制。我们表明，这种相位调制可用于在双光子激发荧光应用中以20kHz的速率切换二元相位图案。
