摘要:
A high resolution optical fault locator for single mode applications uses a high power, short wavelength laser for generating narrow optical pulses that are launched into a single mode fiber under test. The laser output is coupled to a multimode coupler whose output is coupled to a multimode output fiber. The multimode output fiber is fusion spliced with a single mode fiber, which is coupled to a front panel connector for connecting the fiber under test to the fault locator. An optical detector that is compatible with the output laser is coupled to the multimode coupler to receive the reflected light from the fiber under test. The high resolution fault locator is useful in examining single mode local area networks where many closely spaced fiber connections exist.
摘要:
An optical pigtail assembly is described wherein the focusing lens through which the laser diode output passes has its planar surface facing the laser instead of its convex surface. This configuration provides greater coupling efficiency when launching 850 nm light from the laser into an optical fiber. In the method of manufacturing the optical pigtail assembly, ultraviolet, UV, cured epoxy is used to bond the elements of the pigtail assembly together. The use of UV cured epoxy overcomes environmental problems and high capital equipment costs associated with other types of laser pigtail assembly manufacturing methods.
摘要:
An array of LEDs is provided having a lens array for collecting divergent light from each LED. Each lens in the array is associated with a respective LED and has a compound shape including a curved surface that may be spherical or may have an offset aspherical shape. The curved surfaces are centered about each side of its associated LED. The lens may alternatively include faceted surfaces that approximate the curved lens surface.
摘要:
The present invention provides an optical system having an array of light emitting semiconductor devices to performing an operation that have multiple characteristics associated with performing the operation. The array includes at least one detector located within the array to selectively monitor multiple characteristics of the light emitting semiconductor devices and is configured to generate a signal corresponding to the selected characteristic. A controller is configured to control the light emitting semiconductor devices in response to the signal from the at least one detector. At least one of the multiple characteristics may be concentrated at an area of the array and the at least one detector may be located within the array at the area of the array to selectively monitor characteristic that is concentrated at the area of the array.
摘要:
The present invention provides an optical array module that includes a plurality of semiconductor devices mounted on a thermal substrate formed with a plurality of openings that function as micro-reflectors, wherein each micro-reflector includes a layer of reflective material to reflect light. Such material preferably is conductive so as to provide electrical connection for its associated semiconductor device.
摘要:
System and methods are disclosed in connection with a reaction at or below the surface of a work object, in the context of a fluid flow fostering the reaction. In some example embodiments, the reaction is fostered by (1) creating fluid flow of an inerting fluid over a surface during exposure of the surface to a predetermined type of light, (2) creating fluid flow comprising a reactive species that reacts with another species at or below the work surface in a predetermined manner and/or (3) creating a fluid flow comprising a catalytic species that catalyzes a reaction in a predetermined manner, e.g., during exposure of the surface to a predetermined type of light. In some example embodiments, a light source is employed that comprises a solid-state light source, e.g., a dense array of solid-state light sources. In at least one of such example embodiments, the reaction is a photoreaction associated with the light source.
摘要:
A method of measuring multiple optical characteristics of an optical device during a single sweep of a swept wavelength optical system cyclically changes an input state of polarization on consecutive optical frequency increments of an optical signal within the wavelength range of the swept wavelength optical system. From the measured output states of polarization a wavelength-dependent Jones matrix is calculated, and from the Jones matrix the multiple optical characteristics are determined, which characteristics may include PDL and DGD.
摘要:
A real-time wavelength calibration scheme for a swept laser generates an electrical signal from a swept optical output of the swept laser that is cyclical with respect to the wavelength of the swept optical output over a defined range of wavelengths. The point on the electrical signal at any given time provides an accurate phase for the swept optical output at that point. The electrical signal in turn is calibrated by generating calibration references from the swept optical output using known absorption lines within the defined range of interest. The wavelength of the swept laser is calibrated as a function of a reference wavelength from the known absorption lines and the phase at the given point.
摘要:
An optical time domain reflectometer (OTDR) is treated as a linear shift-invariant system modeled as a ideal resistive-capacitive network. A step pulse is applied to a fiber under test and the return optical energy from the fiber under test is converted to signal samples representative of the return optical energy. The signal samples are processed in a controller for producing step impulse stimulus signal samples corrected for the bandwidth limited system response of the optical time domain reflectometer by modeling the OTDR as an exponential linear shift-invariant system that includes the optical transmitter, optical receiver and the fiber under test. The controller takes the time derivative of the step impulse stimulus signal samples for generating signal samples representative of the impulse response for the fiber under test. Standard OTDR interrogating pulses may be used to produce signal samples representing the ideal impulse response with bandwidth correction over the region of the pulsewidth for improved event dead zone accuracy.
摘要:
An active avalanche photo-diode, APD, gain control circuit for use in an optical receiver includes a bias generator for varying the bias on a variable gain APD in response to bias control values generated by a controller. The controller receives the output of the optical receiver and determines the system noise of the receiver for the various bias control values. The system noise is compared to a threshold value for establishing the optimum bias for optimum gain of the APD. The gain control circuit is useable in an optical receiver in an optical time domain reflectometer, OTDR, for increasing the dynamic range of the OTDR.