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Signal beam

About: Signal beam is a research topic. Over the lifetime, 1881 publications have been published within this topic receiving 20717 citations.


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Patent
Masaki Hirota1, Okada Junji1, Funada Masao1, Takashi Ozawa1, Kenji Kawano1, Masahiro Taguchi1 
24 Oct 1996
TL;DR: In this article, an optical bus for transmitting an optical signal, which has diffusers distributed in a optical transmission layer to diffuse an input signal beam and propagate the diffused signal beam, and a signal processor for carrying out signal processing including transmission and reception of a signal beam using the optical bus.
Abstract: To improve resistance to environmental changes and enhance system extensibility, the present invention provides an optical bus for transmitting an optical signal, which has diffusers distributed in a optical transmission layer to diffuse an input signal beam and propagate the diffused signal beam, and a signal processor for carrying out signal processing including transmission and reception of a signal beam using the optical bus.

51 citations

Journal ArticleDOI
TL;DR: In this article, a self-organized light-wave network (SOLNET) is proposed for three-dimensional (3-D) optical wiring with optical Z-connections, where the self-organization is generated in a photorefractive material by self focusing of the two write beams from the two devices.
Abstract: This paper presents core technologies for a self-organized microoptical system (SELMOS) within optoelectronic computers; mass-productive fabrication processes of waveguide films and new types of self-organized lightwave networks (SOLNETs) for three-dimensional (3-D) optical wiring with optical Z-connections. Waveguide films are fabricated by the built-in mask method, which is reusable and can construct surface-normal mirrors/filters at one time within photolithographic accuracy. Beveled core edge walls are made by the tilted ultraviolet (UV) exposure through the built-in mask using a photodefinable material. Near- and far-field patterns reveal that the walls act as micromirrors for optical Z-connections. SOLNET is a network consisting of self-organized coupling waveguides between misaligned optical devices. The self-organization is generated in a photorefractive material by self-focusing of the two write beams from the two devices. Direct SOLNET, where wavelengths of the write beam and the signal beam are the same, is demonstrated using a laser diode. Reflective SOLNET, where one of the two write beams is replaced with a reflected write beam from the edge of the coupled device, realizes two-beam-writing SOLNET in a one-beam-writing configuration. It is especially effective when the coupled device cannot transmit write beams. The proof-of-concept is demonstrated both theoretically and experimentally. These results indicate a possibility to form 3-D optical wiring simply in SELMOS.

51 citations

Journal ArticleDOI
TL;DR: In this paper, a pulsed optical parametric generator (OPG) and a near-infrared distributed feedback diode (DFD) laser are used to generate the signal of the (0, 0) vibrational band.
Abstract: We report the development and application of pulsed optical parametric generator (OPG) and optical parametric oscillator (OPO) systems that are injection seeded with near-infrared distributed feedback diode lasers. The OPG is injection seeded at the idler wavelength without the use of a resonant cavity. Two counter-rotating, beta-barium-borate (β-BBO) crystals are used in the OPG. These crystals are pumped by the third harmonic, 355-nm output of an injection-seeded Nd:YAG laser. An OPO version of the system has also been developed by placing two flat mirrors around the two β-BBO crystals to form a feedback cavity at the signal wavelength. The OPO cavity length is not actively controlled. The output signal beam from the OPG or OPO is amplified using an optical parametric amplifier (OPA) stage with four β-BBO crystals. The frequency bandwidths of the signal and idler laser radiation from OPG/OPA and OPO/OPA systems have been determined to be slightly greater than 200 MHz. The temporal pulses from each system are smooth and near-Gaussian. High-resolution optical absorption measurements of acetylene (C2H2) were performed as another check of the frequency spectrum of the idler beam. The frequency-doubled signal output of the OPO/OPA system was used to perform high-resolution, single-photon, laser-induced fluorescence (LIF) spectroscopic studies of the (0,0) vibrational band of the A 2Σ+−X 2Π electronic transition of nitric oxide (NO) at low pressure. Excellent agreement was obtained between the theory and the experiment. The signal output of the OPG/OPA system was also used for sub-Doppler, two-photon LIF spectroscopic studies of the same vibration–rotation manifold of NO.

51 citations

Patent
31 Dec 1975
TL;DR: In this article, a wideband holographic information storage system was proposed to record Fourier holograms on film in rapid succession, each hologram storing 128 bits of data, and the hologram fringe pattern was held stationary by varying the reference beam frequency to track the variations of frequency of the signal beam that are caused by acoustic-optic modulation of signal beam.
Abstract: A wideband holographic information storage system records Fourier holograms on film in rapid succession, each hologram storing 128 bits of data. The hologram fringe pattern is held stationary by varying the reference beam frequency to track the variations of frequency of the signal beam that are caused by acoustic-optic modulation of the signal beam. Holograms are successively recorded in adjacent positions by scanning a light beam across a photosensitive film with a rotating polygonal mirror, the recording light beam being wide enough to cover two facets of the mirror so as to achieve nearly 100% scanning duty cycle. During readout, a readout light beam is steered to compensate for prismatic deflection effects caused by variations in thickness of the film. The direction of the output beam is maintained constant despite a scanning motion of the incident readout beam, by reflecting the output beam a second time from a different facet of the polygonal mirror to compensate the rotational component of beam motion. Clocking of output data is self-synchronized, based upon modulation signals. Acoustically caused defocusing of the light beam is optically corrected. Methods are employed to reduce crosstalk.

50 citations

Patent
10 Jun 1997
TL;DR: In this article, a laser absorption sensor system for performing optical measurements on a sample is described, which includes a tunable laser, capable of being tuned at rates exceeding 1 KHZ, and with a tuning range approaching 1 GHz.
Abstract: A laser absorption sensor system for performing optical measurements on a sample is described. The sensor system includes a tunable laser, capable of being tuned at rates exceeding 1 KHZ, and with a tuning range approaching 1 GHz. The laser beam is modulated at a modulation frequency between 1 and 100 KHz. Modulation in this frequency range is termed wavelength modulation. The beam is split into two beams, a signal beam and a reference beam. The signal beam traverses the sample where characteristic absorption takes place and is incident on a signal photodetector. The reference beam is incident directly on a reference photodetector. A noise cancellation circuit combines signal and reference photo-currents from signal and reference photodetectors reducing signal noise and increasing system sensitivity. The combination of wavelength modulation and the noise cancellation scheme provide a highly sensitive simple, rugged, low cost laser absorption sensor system.

50 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202215
202131
202040
201929
201844