Abstract: A ferroelectric material 44 is selectively poled using laser light 14 capable of being absorbed by the material 44, a shutter 18 for turning the light on and off, a variable attenuator 28, with a beam splitter 31 and an optical detector 31a, to set the laser power level, a lens 32 to provide focused laser light 14d, a mirror 36 driven by a motor 40 (mirror-scanner) to direct the light to the regions to be poled, and an electric field applied by electrodes 68, 70. A computer 24 provides automatic control over selective poling of the material 44 by controlling the shutter 18, variable attenuator 28, mirror 36 position, and the direction of the applied electric field. A temperature sensor 52 provides temperature feedback to ensure proper laser power and dwell time. In the alternative, the material 44 is covered with a mask 604 and scanned with the laser to provide selective pole reversal.

Abstract: A single-side growth reflection-based photodetector includes a waveguide structure 8 comprising a "strip-loaded rib" waveguide 10 which accepts light 11 from an input end-face 7 and confines the light to a predetermined spatial optical mode 12. The light 11 propagates along the waveguide 10 and is internally reflected off an edge 18 of a retrograde angled region 20, at one end of the waveguide, to a detector layer 16 where the light 11 is absorbed, thereby creating electron-hole pairs in the detector layer 16. The absorbed light is detected by a metal-semiconductor-metal (MSM) detector comprising an interdigital electrode structure 14 disposed on the outer surface of the detector layer 16 which is disposed above a wide non-waveguide mesa layer 9. For 0.84 micron wavelength light, the detector layer 16 is made of GaAs. Alternatively, for 1.3-1.55 micron light, the detector layer 16 is made of InGaAs.

Abstract: An integrated optical receiver/transmitter (transceiver) 8 has continuous wave (cw) light 16 that enters a Mach-Zehnder optical modulator 10 controlled by a modulator control circuit 12 that provides modulated light 30 along a waveguide 32 to an optical coupler 34 which couples a predetermined portion of the light 30 to a waveguide 44 as light 42 which then exits the transceiver from a port 46. Receive light 90 is accepted at the port 46 and travels along the waveguide 44 to the coupler 34 which couples a predetermined amount of the light 90 to a waveguide 70 as light 92 which is detected by a waveguide-integrated photodetector 72. The photodetector 72 provides a current signal on a line 74 to a receiver circuit 76 which provides a voltage signal indicative of the light 92. Alternatively, the coupler may be passive, thereby not requiring the coupler control circuit, or no coupler at all may be employed and two fibers used for communications with the transceiver 8.

Abstract: A method and apparatus for forming tapered thickness and material content of III-V material, or alloys thereof, in particular GaAs and AlGaAs, by gradient thermal heating of substrates during epitaxial growth and the optoelectronic structures formed thereby.