Using a composite photonic-crystal structure composed of both a square and rectangular lattice, scientists successfully realize an on-chip semiconductor laser whose emitted beams can be dynamically controlled by varying their relative lattice constants.

On-chip beam-steering photonic-crystal lasers

We propose a novel beam-steering device based on a slow-light waveguide amplifier. In this paper, we present the idea of this steering technique and show its modeling characteristics. Giant steering of the radiation beam is obtained by tuning the wavelength of input light, which is coupled into the Bragg reflector waveguide. A tunable deflection-angle range can be over 40 degrees. High beam coherency and flat intensity distribution enable us to obtain an ultra-large number of resolution-points over 1,000 for few-millimeter long devices.

Giant and high-resolution beam steering using slow-light waveguide amplifier.

We report on a novel concept to create beam-steering lasers using photonic crystals. The lasers that we have developed indeed emit beams over a range of directions. The maximum beam steering angle is ∼±30°.

A number of instruments use rasters generated by deflecting one or more laser beams with some scanning device. Optics for shaping and manipulating these beams are described, with particular attention to the dual role of each element in terms of the (instantaneous) beam and the scanned pattern. A solution is shown to the problem of chromaticity in diffraction scanners. Specific examples are drawn from the scanning laser ophthalmoscope, a scanning instrument using two lasers with real-time TV display.

Optics for laser rasters.

A wide angle microscanning architecture is presented in which the angular deflection is achieved by displacing the principle axis of a curved silicon micromirror of acylindrical shape, with respect to the incident beam optical axis. The micromirror curvature is designed to overcome the possible deformation of the scanned beam spot size during scanning. In the presented architecture, the optical axis of the beam lays in-plane with respect to the substrate opening the door for a completely integrated and self-aligned miniaturized scanner. A micro-optical bench scanning device, based on translating a 200 μm focal length micromirror by an electrostatic comb-drive actuator, is implemented on a silicon chip. The microelectromechanical system has a resonance frequency of 329 Hz and a quality factor of 22. A single-mode optical fiber is used as the optical source and inserted into a micromachined groove fabricated and lithographically aligned with the microbench. Optical deflection angles up to 110 degrees are demonstrated.

Integrated wide-angle scanner based on translating a curved mirror of acylindrical shape.

A high quality nonimpact printer at a speed of 10,000 1/min is realized by a new laser scanning system and an electrophotographic process. The laser scanning system uses a parabolic mirror for correcting line scanning distortion. When a polygonal mirror facet is placed on the axis of the parabolic mirror at about two-thirds of the focal length from the mirror surface, and the focus of the parabolic mirror is on a photosensitive drum surface. The scanning velocity distortion is reduced to less than 0.1% over ±30° of the scanning angle. The confusion circle induced by the parabolic mirror is 1 order of magnitude smaller than the spot size determined by diffraction limit. The tolerance of the length from the rotating mirror to the parabolic mirror for 0.1% distortion over ±30° scanning angle is 10% of focal length. This high speed laser printer has demonstrated the high quality printing of 10-dots/mm resolution.

Laser printer scanning system with a parabolic mirror.

PURPOSE:To enable the facsimile, light printer equipments, etc. to compensate the image distortion and also minimize the scanning distortion by installing a paraboloid reflector.

Scanning light distortion compensator

PURPOSE:To provide a distorsion compensating device for a scanning light, in which a scanning starting point and a projecting plane are located in such a position relative to a parabolic mirror that the sanning point takes an approximately constant level, thereby to improve the distorsions in focusing and scanning of the scanning light.

Distorsion compensating device for scanning light

Laser printer scanning system with a parabolic mirror

PURPOSE:It is a purpose of the invention to provide a supersonic light deflector whereby each deflected light output is made to have the same intensity or arbitrary one against fixed firectional incident light.

Abe Fumitaka

Papers

Laser printer scanning system with a parabolic mirror.

Scanning light distortion compensator

Distorsion compensating device for scanning light

Laser printer scanning system with a parabolic mirror

Supersonic light deflector