Abstract: The present invention provides configurations for an electro-optically tunable filter. The filter includes an electro-optical crystal, at least one electrically conductive mesh screen, at least one electrode and a voltage source. In one embodiment, an electrical voltage passes from a source to a mesh screen contacting the crystal, through the crystal and an electrode on the crystal's opposite end. The mesh screen creates a narrow bandpass. The optical properties of the mesh screen-crystal combination are determined partially by the refractive index of the crystal when a voltage is applied to the mesh screen. Variable voltages change the refractive index of the crystal, creating varying spectral positions of the filter. Application of a voltage between the mesh screen and the electrode creates a field internal to the crystal that changes its refractive index, allowing it to be tunable in the bandpass location thereby affecting a passing light signal.

Abstract: The present invention provides configurations for an electro-optically tunable filter. The filter includes an electro-optical crystal, at least one electrically conductive mesh screen, at least one electrode and a voltage source. In one embodiment, an electrical voltage passes from a source to a mesh screen contacting the crystal, through the crystal and an electrode on the crystal's opposite end. The mesh screen creates a narrow bandpass. The optical properties of the mesh screen-crystal combination are determined partially by the refractive index of the crystal when a voltage is applied to the mesh screen. Variable voltages change the refractive index of the crystal, creating varying spectral positions of the filter. Application of a voltage between the mesh screen and the electrode creates a field internal to the crystal that changes its refractive index, allowing it to be tunable in the bandpass location thereby affecting a passing light signal.

Abstract: We describe a device for aligning optical beams that uses either an elliptically curved or a parabolically curved mirror arranged in the reflected beam path between a rotatable mirror, which is placed at the focus of the curved mirror, and the desired target. With the elliptical mirror, the device provides variable angle, fixed position of incidence of the reflected beam upon a target placed at the second focus of the ellipse. With the parabolic mirror, the device provides variable position, fixed angle of incidence of the reflected beam upon a target. Combinations of these devices may be used to solve a variety of beam steering and/or beam alignment problems. These devices are particularly useful for experiments and applications involving ultrashort optical pulses since the time of flight through either of these devices is a constant independent of the angle of incidence and the position of incidence.

Abstract: An optical probe for collecting light from a defined region in a high temperature environment employs a pair of curved surfaces and a reflective surface to couple light from the defined area into an optical fiber while discriminating against light from other regions.