Abstract
Laser light, which is doubly phase modulated by an ultrasonic wave, can be utilized for speckle reduction. The double phase modulation is found to be more effective for speckle reduction than single phase modulation, since the doubly modulated laser beam for illumination is much degraded in spatial coherence with the same ultrasonic conditions. Average contrast is discussed analytically and experimentally as a measure of image-speckle reduction. Agreement between the measured and calculated results are recognized to the extent that the ultrasonic wave can be regarded as a pure phase grating. The average contrasts for two kinds of diffuser decrease similarly down to a minimum of ~0.4 by increasing the ultrasonic power.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.