31 results about "Coherence effect" patented technology

An optical inspection system rapidly evaluates a substrate by illumination of an area of a substrate larger than a diffraction-limited spot using a coherent laser beam by breaking temporal or spatial coherence. Picosecond or femtosecond pulses from a modelocked laser source are split into a plurality of spatially separated beamlets that are temporally and / or frequency dispersed, and then focused onto a plurality of spots on the substrate. Adjacent spots, which can overlap by up to about 60-70 percent, are illuminated at different times, or at different frequencies, and do not produce mutually interfering coherence effects. Bright-field and dark-field detection schemes are used in various combinations in different embodiments of the system.

A zero power identical pair of oppositely-oriented meniscus lens elements mounted in the projection light path, serves as curved mask support while compensating for optical anomalies such as beam shift and beam deviations produced by other transparent supports for the curved mask. The zero-power meniscus lens pair, without affecting the transmission beam characteristics, lets the beam diffract as efficiently as does a regular planar mask, thus preserving the partial coherence effects and resolution concepts of projection lithography. This simple but novel optics device is not only expected to clear several barriers for curved mask projection lithography but also find place in other applications where collimated or converging light beams have to travel extra paths without significant aberration.

An optical inspection system rapidly evaluates a substrate by illumination of an area of a substrate larger than a diffraction-limited spot using a coherent laser beam by breaking temporal or spatial coherence. Picosecond or femtosecond pulses from a modelocked laser source are split into a plurality of spatially separated beamlets that are temporally and / or frequency dispersed, and then focused onto a plurality of spots on the substrate. Adjacent spots, which can overlap by up to about 60-70 percent, are illuminated at different times, or at different frequencies, and do not produce mutually interfering coherence effects. Bright-field and dark-field detection schemes are used in various combinations in different embodiments of the system.

A rotatable compensator configured to transmit non-collimated light over a broad range of wavelengths, including ultraviolet, with a high degree of retardation uniformity across the aperture is presented. In one embodiment, a rotatable compensator includes a stack of four individual plates in optical contact. The two thin plates in the middle of the stack are made from a birefringent material and are arranged to form a compound, zeroth order bi-plate. The remaining two plates are relatively thick and are made from an optically isotropic material. These plates are disposed on either end of the compound, zeroth order bi-plate. The low order plates minimize the sensitivity of retardation across the aperture to non-collimated light. Materials are selected to ensure transmission of ultraviolet light. The optically isotropic end plates minimize coherence effects induced at the optical interfaces of the thin plates.

Embodiments disclosed herein generally relate to a HAMR device for use in a magnetic reading system. The HAMR device has a primary waveguide extending from a media facing surface to a surface opposite the media facing surface. In one embodiment, the HAMR head has a secondary waveguide having a first and second end positioned within the HAMR head. The secondary waveguide is positioned near the primary waveguide, and the first and second ends of the secondary waveguide are non-reflecting. A thermal sensor is coupled to the secondary waveguide, and responds only to optical power fluctuations in the primary waveguide. In another embodiment, the HAMR head has a second thermal sensor rather than a secondary waveguide. The first thermal sensor and the second thermal sensor are coupled together to act as one optical power sensor and are disposed on the primary waveguide.

The invention discloses a double-color all-optical switch based on a quantum well inter-subband transition cavity-induced coherence effect, and belongs to the technical field of semiconductor materials. According to the structure of the double-color all-optical switch, an AlAs layer (2), a first barrier layer (3), a first quantum well layer (4), a second barrier layer (5), a second quantum well layer (6), a third barrier layer (7), a third quantum well layer (8), a fourth barrier layer (9) and a continuous area (10) sequentially grow on a substrate (1) made of GaAs materials, a cycle is from the first barrier layer (3) to the continuous area (10), six to fifteen cycles are arranged, and then a covering layer (11) and an air isolation layer (12) are provided. The double-color all-optical switch based on the quantum well inter-subband transition cavity-induced coherence effect can work at a medium-far infrared wave band, serves as a complete band gap switch of an infrared radiation source with low energy consumption and high efficiency, and has application value on the aspects of satellite detection and communication. The structure and materials of the double-color all-optical switch can be selected artificially, and the double-color all-optical switch has the advantages of easily achieving a wide wave band, miniaturization and integration.

The invention discloses a frequency spectrum generation device and a physical quantity change amount measurement device and method. The device and method adopt an optical parametric oscillator in a compact structure to convert continuous single-frequency laser in an optical communication wave band into a squeezed light field in the optical communication wave band, thereby effectively reducing the de-coherence effect due to loss when the continuous variable squeezed light field transmits in an optical fiber, and maintaining compression degree to be maximum degree to allow the squeezed light field not to be damaged when transmitting in the fiber; and the squeezed light field in the optical communication wave band is injected to a vacuum channel of a fiber Mach-Zehnder interferometer, so that quantum precision measurement lower than shot noise limit is realized, and sensitivity of the fiber Mach-Zehnder interferometer is improved. The device is ingenious in structure, high in anti-interference capability and high in sensitivity, and is more suitable for measurement of tiny physical quantity change amount.

The invention relates to the movable target positioning technology, in particular to an accurate positioning method based on the echo coherence effect, and solves the problem that the conventional underground personnel positioning technology has a high positioning ambiguity. The method comprises the following steps: (1), a detection waveform with a favorable self-correlation performance is designed; (2), an identification sensor sends a calling signal to an identification card carried by underground personnel periodically, and the identification card sends an echo signal to the identification sensor; (3), a coherence receiver receives the echo signal while moving unceasingly, and the detection waveform in the echo signal completely coincides with the detection waveform input in the coherence receiver when the coherence receiver moves to a position where the round-trip-delay of the echo signal is a specific value T; and (4), and the distance L between the identification sensor and the identification card is calculated out according to the round-trip-delay T. The method has the advantage that the problem that conventional underground personnel positioning technology has a high positioning ambiguity is solved, so as to be suitable for underground personnel positioning in a coal mine.

The disclosed testing device for laser phase noise comprises: a phase noise conversion device with two polarization beam-splitting lens (1) and (3), and an atom gas chamber or molecule gas chamber (2). Wherein, coupling two beam linear polarization light by (1) to spread into (2), converting the phase noise into amplitude noise by electromagnetic induced coherence effect, using (3) to divide the detecting light and coupling light, and using a balance zero-beat system to detect the outgoing noise. This invention simplifies device fit to mobile and wide application.

The invention discloses an automatic weighing, sealing and seaming device for a wire and cable material, and belongs to the technical field of packaging machinery for plastic particles for the wires and cables. The automatic weighing, sealing and seaming device comprises a weighing device supported on the terrace under a used state, a sealing device, a seaming device and a packaging bag supporting device, and is characterized in that the weighing device, the sealing device and the seaming device are arrayed on the same straight line in an arranging manner of left to right; the packaging bag supporting device is supported on a terrace of the use place at the position simultaneously corresponding to the lower parts of the front sides of weighing device, the sealing device and the seaming device. The automatic weighing, sealing and seaming device achieves a good coherence effect; the space is saved, and the adaptability to a packaging place is improved; the labor investment is reduced; furthermore, the sealing efficiency is improved; the labor intensity of an on-line worker is relieved, and the labor cost is reduced so as to save precious labor resources; the sealing quality is guaranteed; the packaging bag can be sealed under a vertical state; the automatic weighing, sealing and seaming device has an effect of preventing the wire and cable material in the bag from leaking from the bag opening.

The invention discloses an atom gas concentration detecting apparatus and a method based on optical coherent backscattering effect. The atom gas concentration detecting apparatus comprises a laser aligner (1), a Glan-Taylor prism (2), a reflector (3), a depolarizing splitting prism (4), a sample beach (5), a Fourier lens (6), a polarization analyzer (7), a detector (8) and a computer (9); the laser aligner (1), the Glan-Taylor prism (2) and the reflector (3) are successively arranged on one same straight line along the transverse direction; the reflector (3) and depolarizing splitting prism (4) are arranged on one same straight line along the vertical direction; the sample beach (5) is arranged at one side of the depolarizing splitting prism (4), and the other side of the depolarizing splitting prism (4) is provided with the Fourier lens (6), the polarization analyzer (7) and the detector (8); the detector (8) is electrically connected with the computer (9) via data lines; and the detector (8) is arranged on the focal plane of the Fourier lens (6). The atom gas concentration detecting apparatus and the method help to realize nondestructive test on atom concentration of the atom gas in an enclosed gas room.