You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither SPIE nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the SPIE website.
28 April 2006LCOS as a reference element in Twyman-Green laser interferometer
Micro-Electro-Mechanical Systems are nowadays frequently used in many fields of industry. The number of their applications increases and their functions become more responsible, therefore precise knowledge about their properties is necessary. Due to its fragility and small sizes non-contact and high sensitive measurement method is required. Two-beam laser interferometry is one of the most popular testing methods of microelements. Such method implemented in Twyman-Green interferometer allows for full-field shape determination and out-of-plane displacement measurement. However the elements under test may bring additional challenges: their surfaces may have complicated shape or large shape gradients which prohibit their testing by means of interferometer with a flat reference mirror. To overcome such problems we propose to use LCOS (Liquid Crystal On Silicon) - phase, reflective SLM as an active reference element. LCOS serves as an adaptive reference mirror and phase shifter. The use of such element allows increasing measurement range of the interferometer and simplifies out-of-plane displacement measurement through object wavefront compensation. The applicability of the modified Twyman-Green interferometer will be shown at the examples of active micromembranes testing.
The alert did not successfully save. Please try again later.
Jacek Kacperski, Malgorzata Kujawinska, Michal Jozwik, "LCOS as a reference element in Twyman-Green laser interferometer," Proc. SPIE 6188, Optical Micro- and Nanometrology in Microsystems Technology, 61881C (28 April 2006); https://doi.org/10.1117/12.663389