摘要:
A spectral filter for an integrated optic application, such as in an optical demultiplexer (14), is provided and includes a common input waveguide (20) integrally connected to a pair of optical output waveguides (22, 24). The material selected for the output waveguides (22, 24) can be semiconductor material that provides a low index of refraction for a specific wavelength in one output waveguide and a relatively higher index of refraction for the same wavelengths in the other output waveguide, the output waveguide materials being interrelated in that they have a common index of refraction for at least one wavelength across the spectrum of radiation. An incident spectrum of radiation (16) can be split into at least a pair of bandwidths of radiation to provide a spectral filter function.
摘要:
A GaAs FET structure with a high electric field region, or active region, contacted by source, gate and drain electrodes is provided which can be used for high speed optical detection or for microwave oscillator optical injection locking. The device provides for efficient coupling of optical radiation into the active region through an opening in a semi-insulating substrate used to support the device. A buffer layer between the active region and the substrate prevents leakage current to the substrate, permits a larger illumination window for improved optical coupling and provides mechanical support for the FET detector. GaAs photodetectors are also provided by eliminating the gate electrode.
摘要:
A diffraction limited working beam at a given frequency is amplified without degrading its diffraction limited quality by diverting a minor portion of the beam as a probe beam, and amplifying the remaining portion of the working beam with a high power pump beam at a different wavelength. The amplification takes place in a host medium that has a rare earth dopant with an energy transition from the pump beam's wavelength to the wavelength of the working beam. The resulting amplified working beam is non-diffraction limited. The probe beam is frequency modulated and coupled with the amplified working beam in a second host medium that also has a rare earth dopant. Energy is transferred from the amplified working beam to the modulated probe beam through a resonant energy transfer in the second host medium, producing an amplified output beam at the working beam frequency that retains the diffraction limited quality of the probe beam.
摘要:
A vehicle lighting system includes one or more central light sources, a plurality of optical loads including headlight lenses, an optical fiber network that extends from the light sources to illuminate the headlight lenses and other optical loads, and optical switches and oscillators that include respective input fibers illuminated from the light source and output fibers to respective optical loads, and operate by enabling and disabling optical connections between their input and output fibers. The headlight assemblies switch between high and low beams by moving their fibers vertically, and control beam diffusion by moving the fibers parallel to the lens axes, including an automatic diffusion adjustment for a headlight reflection from a vehicle in front. The switches include various mechanisms for moving the input and output fibers into and out of alignment with each other, including a shaped resilient sleeve, a hinge pivotally joining the fibers, an opaque shutter with a transmissive section movable between the fibers, and also a liquid-based switch that relies upon total internal reflection. A feedback mechanism for some of the switches dims the source lamp when the switch is OFF to conserve energy. The oscillators operate by normally urging an input fiber towards an OFF position, at which it actuates a mechanism that shifts it to an ON position at which the mechanism is deactivated. A failsafe system employs multiple light sources, with each source sharing its light output with the load for another source that has failed.
摘要:
A method of forming a tapered optical waveguide within a substrate (2). An appropriate substrate (2) is coated with a layer of barrier material (4) such as silicon dioxide which provides a relatively tight matrix relative to the open matrix of the substrate (2). The barrier material (4) is deposited on the substrate with a sloping variable thickness that is inversely related to the desired depth of the waveguide taper. The barrier material (4) can be deposited through a vacuum deposition technique and subsequently subjected to ion-milling to provide the desired taper. An appropriate source of metal ions (6), such as silver, capable of being transferred, such as by diffusion into the substrate (2) for increasing the refractive index and thereby defining a waveguide, is then transmitted to and through the barrier material (4). The metal (6) may be coated on the tapered barrier material (4), and then diffused into the substrate (2) through the barrier material (4) which provides a controlled transmission of the ions proportional to its thickness. The substrate ( 2) can then be cleaned to strip both the barrier material (4) and residual metal (6) for subsequent processing. The resulting product of this process is a superior tapered optical waveguide device that can be economically manufactured.
摘要:
A GaAs FET structure with a high electric field region, or active region, contacted by source, gate and drain electrodes is provided which can be used for high speed optical detection or for microwave oscillator optical injection locking. The device provides for efficient coupling of optical radiation into the active region through an opening in a semi-insulating substrate used to support the device. A buffer layer between the active region and the substrate prevents leakage current to the substrate, permits a larger illumination window for improved optical coupling and provides mechanical support for the FET detector. GaAs photodetectors are also provided by eliminating the gate electrode.
摘要:
In accordance with one embodiment of the invention, a microwave signal is used to modulate a laser diode and the resultant modulated light output energy from the laser diode is applied through an optical fiber waveguide to the active solid state component in a microwave oscillator circuit such that the output signal from the microwave oscillator is phase locked to the modulation carried by the light energy. The invention allows optical injection phase locking to be achieved not only at the fundamental frequency of the modulating signal, but also at various harmonics thereof; and "on-off" switching of the microwave oscillator can be controlled simultaneously with phase locking.
摘要:
A wideband, true time delay antenna beamforming network 10 for millimeter wave phased array antennas is disclosed herein. The beamforming network 10 of the present invention includes a laser 30 for generating a beam B of electromagnetic energy. The beamforming network 10 further includes an electro-optic modulator 40 for modulating the beam B in response to an input signal S modulated about a first frequency f.sub.o. A first antenna array 80 generates a first electromagnetic field pattern P by radiating the modulated beam B' in a first direction. The present invention further includes a constrained lens 90 for receiving the first field pattern P and for emitting an antenna driver feed beam F in a second direction in response thereto. An antenna array driver 115 electro-magnetically coupled to the constrained lens 90 by the feed beam F provides a set of signals modulated about the first frequency f.sub.o to drive an antenna array 20.
摘要:
A thermally insulated distributed light network employs an array of discrete, thermally insulative light guides that are spaced slightly away from a central light source and provide optical coupling to optical fibers that have a lower thermal capability. The light guides can either be solid such as quartz, focusing lenses, or a combination of the two. The light receiving ends of the light guides are preferably held by a specially designed coupler so that the guides do not diverge from each other by more than the fibers' optical acceptance angle. The light guides are shaped so that their adjacent edges touch and form an enclosure around the light source, and the fibers are provided in bundles with matching geometries. The network includes an edge-lit display panel that is illuminated by a fiber that has either internal light scattering centers in the form of reflective particles or gas bubbles, or a series of edge notches, to redirect light into the panel.
摘要:
A vehicle lighting system includes one or more central light sources, a plurality of optical loads including headlight lenses, an optical fiber network that extends from the light sources to illuminate the headlight lenses and other optical loads, and optical switches and oscillators that include respective input fibers illuminated from the light source and output fibers to respective optical loads, and operate by enabling and disabling optical connections between their input and output fibers. The headlight assemblies switch between high and low beams by moving their fibers vertically, and control beam diffusion by moving the fibers parallel to the lens axes, including an automatic diffusion adjustment for a headlight reflection from a vehicle in front. The switches include various mechanisms for moving the input and output fibers into and out of alignment with each other, including a shaped resilient sleeve, a hinge pivotally joining the fibers, an opaque shutter with a transmissive section movable between the fibers, and also a liquid-based switch that relies upon total internal reflection. A feedback mechanism for some of the switches dims the source lamp when the switch is OFF to conserve energy. The oscillators operate by normally urging an input fiber towards an OFF position, at which it actuates a mechanism that shifts it to an ON position at which the mechanism is deactivated. A failsafe system employs multiple light sources, with each source sharing its light output with the load for another source that has failed.