Transparent flexible membrane i.e. protection film, deformation contactless measurement device for photomask cleaning and depolluting device, has isolation unit receiving and isolating reflected light beam to measure membrane displacement

摘要

The device has a generating unit (3) with a laser source for generating an incident light beam (I) having a wavelength around 900 nanometer, and for obliquely directing the light beam towards a transparent flexible membrane (1). An isolation unit (5) receives and isolates the reflected light beam (4') to measure displacement of the membrane, where the light beam is reflected by the membrane. The incident light beam makes an incidence angle with a surface of the membrane, and interacts with a central zone of the membrane.