Abstract:
Beam position and beam width sensing is accomplished by scattering a small percentage (0.1 percent) of the beam energy. The scattered light is analyzed by an arrangement of three photosensors that compare the energy distribution along different portions of the beam and produce appropriate error signals which are then used to reposition and focus the beam. Scattering is accomplished by means of thin threads disposed across the wavepath.
Abstract:
This application describes a variety of circuit components for use at optical frequencies. Each of the components is formed from one or more transparent dielectric strips embedded in a transparent substrate of slightly lower refractive index. By suitably shaping and locating the guiding strips, power dividers, modulators, directional couplers, and a variety of filters can be realized. Tuning arrangements are also disclosed.
Abstract:
Special multiplexing of a plurality of N beams in a beam transmission system comprising a sequence of confocally spaced lenses is accomplished by directing the beams such that p separate groups of q beams are formed at odd lenses in said sequence of lenses, and q separate groups of p beams are formed at even lenses in said sequence, where p and q are integers greater than one and p X q N. The beams are resolved at the output end into N separate beams. A similar arrangement can be employed using nonconfocally spaced lenses or a continuously focusing waveguide.
Abstract:
Unwanted longitudinal modes, typically generated by a laser oscillator, are suppressed by replacing one of the two uniformly reflecting cavity mirrors with a pair of longitudinally spaced apertured mirrors. Between themselves, the apertured mirrors form an auxiliary cavity supportive of a set of longitudinal modes that are different than the set supported by the primary cavity. As a result, the laser can only oscillate at those frequencies common to both resonant cavities. The mode selectivity is made continuously variable by providing means for changing the relative size of the beam and the apertures in the auxiliary cavity mirrors.
Abstract:
THIS APPLICATION DESCRIBES A VARIETY OF CIRCUIT COMPONENTS FOR USE AT OPTICAL FREQUENCIES. EACH OF THE COMPONENTS IS FORMED FROM ONE OR MORE TRANSPARENT DIELECTRIC STRIPS EMBEDDED IN A TRANSPARENT SUBSTRATE OF SLIGHTLY LOWER REFRACTIVE INDEX. BY SUITABLY SHAPING AND LOCATING THE GUIDING STRIPS, MODULATORS, DIRECTIONAL COUPLERS, AND A VARIETY OF FILTERS CAN BE REALIZED. TUNING ARRANGEMENTS ARE ALSO DISCLOSED.