Comparison of different SLM-based aberration measurement and correction methods

For microscopic imaging system and optical tweezers it is desired to reduce aberrations to a very low level. This way good Strehl ratios can be achieved. Unfortunately, even well corrected systems can suffer from aberrations that are introduced by the specimen. Therefore, static correction is not sufficient and one possibility to eliminate such aberrations is to employ a spatial light modulator. We present different aberration measurement and correction methods using a high resolution liquid crystal display (LCD) as a pure phase modulator. With all the methods the LCD is located in the pupil plane and the correction can be achieved by software. A short discussion concerning the advantages and disadvantages of the different methods will be given.