ACOUSTO-OPTICAL TUNABLE FILTER ELEMENT

摘要

An acousto-optical filter element (114) is provided which has an acousto-optical crystal (118) having an acoustic signal transmitter (120) for generating acoustic signals in the acousto-optical crystal (118). The acousto-optical crystal (118) is designed to selectively spatially deflect light of a target wavelength from an input light beam (116) entering into the acousto-optical crystal (118), as a function of a high frequency applied to the acoustic signal transmitter (120), and to thereby produce a target light beam (126) having the target wavelength. In addition, the acousto-optical filter element (114) includes a spatial filter element (132) which is located in the target light beam (126) and is designed to selectively suppress the intensity of the target light beam (126) in a plane perpendicular to the propagation direction of the target light beam (126).

主权项

1. An acousto-optical filter element comprising:
an acousto-optical crystal having an acoustic signal transmitter for generating acoustic signals in the acousto-optical crystal, the acousto-optical crystal configured to selectively spatially deflect light of a target wavelength from an input light beam of a broadband coherent light source entering into the acousto-optical crystal, as a function of a high frequency applied to the acoustic signal transmitter, and to thereby produce a target light beam having a desired target wavelength; and a spatial filter element located in the target light beam, the spatial filter element configured to selectively suppress the intensity of a portion of the target light beam in a plane perpendicular to the propagation direction of the target light beam, the spatial filter element comprising a pinhole and a lens element, the pinhole cutting off unwanted side modes of a spatial transfer function of the target light beam.