Abstract:
Various embodiments of a micro-disc modulator as well as a silicon photonic device and an optoelectronic communication apparatus using the micro-disc modulator are described. In one aspect, a device includes a SOI substrate and a silicon photonic structure formed on a primary surface of the SOI substrate. The semiconductor substrate includes a silicon waveguide and a micro-disc modulator. The micro-disc modulator is adjacent to the silicon waveguide and has a top surface substantially parallel to the primary surface of the SOI substrate. The top surface of the micro-disc modulator includes one or more discontinuities therein. The micro-disc modulator may be a multi-junction micro-disc modulator having two vertical p-n junctions with a single resonance frequency to achieve high-speed modulation and low-power consumption.
Abstract:
An arrangement 10 for efficiently generating tunable pulsed laser output at 8-12 microns. The arrangement 10 includes a laser 12, a first optical parametric oscillator 14 of unique design, and a second optical parametric oscillator 22. The first oscillator 14 is constructed with an energy shifting crystal 20 and first and second reflective elements 16 and 18 disposed on either side thereof. Energy from the laser 12 at a first wavelength is shifted by the crystal and output at a second wavelength. The second wavelength results from a secondary process induced by a primary emission of energy at a third wavelength, the third wavelength resulting from a primary process generated from the first wavelength in the crystal. Mirror coatings are applied on the reflective elements 16 and/or 18 for containing the primary emission and enhancing the secondary process. The second optical parametric oscillator 22 then shifts the energy output by the first OPO 14 at the second wavelength to the desired fourth wavelength. In the illustrative embodiment, the first optical parametric oscillator 14 includes an x-cut ribidium titanyl arsenate crystal 20 and the second optical parametric oscillator 22 includes a silver gallium selenide crystal. The first wavelength is approximately 1.06 microns, the second wavelength is approximately 3.01 microns, the third wavelength is approximately 1.61 microns, and the fourth wavelength is in the range of 8-12 microns.
Abstract:
A chemical sensing system and method. The system (10) includes a transmitter (20) having a laser (200) for providing a collimated beam of electromagnetic energy at a first frequency and a Q switch (230) in optical alignment with the beam. The system further inlcudes a crystal for shifting the frequency of the beam from the first frequency to a second frequency. A mechanism is included for shifting the beam from the second frequency to a third frequency in the range of 8-12 microns. Ideally, the input beam is provided by a neodymium-YAG laser and the Q switch is a passive Q switch. The crystal is x-cut potassium titanyl arsenate. The system includes a mechanism for switching the polarization state of the second beam and providing third and fourth beams therefrom. The third beam has a first polarizaion and the fourth beam has a second polarization. The second polyrization is orthogonal relative to the first polarization. The mechanism for shifting the beam from the second frequency to the third frequency includes first and seccond optical parametric oscillators (250 and 271), each optical parametric oscillator including a cadmium selenide crystal. The frequency shifted third and fourth beams are combined to provide an output beam in the range of 8-12 microns. The output beam is transmitted and a return signal therefrom is detected by a receiver in the illustrative chemical sensing application.
Abstract:
A supercontinuum optical pulse source provides a combined supercontinuum. The supercontinuum optical pulse source comprises one or more seed pulse sources (13), and first and second optical amplifiers (7) arranged along first and second respective optical paths. The first and second optical amplifiers are configured to amplify one or more optical signals generated by said one or more seed pulse sources. The supercontinuum optical pulse source further comprises a first microstructured light-guiding member (9) arranged along the first optical path and configured to generate supercontinuum light responsive to an optical signal propagating along said first optical path, and a second microstructured light-guiding member (9) arranged along the second optical path and configured to generate supercontinuum light responsive to an optical signal propagating along said second optical path. The supercontinuum optical pulse source further comprises a supercontinuum-combining member (5) to combine supercontinuum generated in at least the first and second microstructured light-guiding members to form a combined supercontinuum. The supercontinuum-combining member comprises an output fibre, wherein the output fibre comprises a silica-based multimode optical fibre supporting a plurality of spatial modes at one or more wavelengths of the combined supercontinuum.
Abstract:
When a wavelength of a first laser beam (23) with which a first recording medium (17) including a first recording layer is recorded and reproduced is indicated as lambda 1 (nm), a wavelength of a second laser beam (24) with which a second recording medium (18) including a second recording layer is recorded and reproduced as lambda 2 (nm), the relationship between the wavelength lambda 1 and the wavelength lambda 2 is set to be expressed by 10
Abstract:
When a wavelength of a first laser beam with which a first recording medium including a first recording layer is recorded and reproduced is indicated as λ1 (nm), a wavelength of a second laser beam with which a second recording medium including a second recording layer is recorded and reproduced as λ2 (nm), the relationship between the wavelength λ1 and the wavelength λ2 is set to be expressed by 10 ≦ |λ1 - λ2| ≦ 120. The first recording layer has a light absorptance ratio of at least 1.0 with respect to the wavelength λ1. The light transmittance of the first recording medium with respect to the wavelength λ2 is set to be at least 30 in both the cases where the recording layer is in a crystal state and in an amorphous state. In order to record and reproduce the optical multilayer disk with the above-mentioned characteristics, a multiwavelength light source with the following configuration is used. Wavelengths of fundamental waves with different wavelengths from injection parts (64-1,64-2) formed at one end of a plurality of optical waveguides (62-1,62-2), which satisfy phase matching conditions different from one another and are formed in the vicinity of the surface of a substrate (61), are converted simultaneously, and the first and second laser beams are emitted from emission parts (66) formed at substantially the same position at the other end of the optical waveguides. This enables an optimum optical system for high density recording and reproduction to be obtained.
Abstract:
An arrangement (10) for efficiently generating tunable pulsed laser output at 8-12 microns. The arrangement (10) includes a laser (12), a first optical parametric oscillator (14) including an x-cut rubidium titanyl arsenate crystal (20) and a second optical parametric oscillator (22) including a silver gallium selenide crystal (20). Energy from the laser (12) at a first wavelength is shifted by the crystal (20) and output at a second wavelength. The second wavelength results from a secondary process induced by a primary emission of energy at a third wavelength, the third wavelength resulting from a primary process generated from the first wavelength in the crystal. Mirror coatings are applied on the reflective elements (16 and/or 18) for containing the primary emission and enhancing the secondary process. The second optical parametric oscillator (22) then shifts the energy output by the first OPO (14) at the second wavelength to the desired fourth wavelength.