A system, method and mirror are provided in order to more reliably detect the presence of an object, such as a person. In the context of a system, the system includes a sensor configured to emit signals having a predefined wavelength and to detect a reflection of the signals having the predefined wavelength. The system also includes a reflective panel positioned relative to the sensor such that the signals emitted by the sensor are directed toward the reflected panel. The system further includes a filter associated with the reflective panel and positioned relative to the sensor such that the signals emitted by the sensor are also directed toward the filter. The filter is configured to attenuate at least signals having the predefined wavelength.

A system, method and mirror are provided in order to more reliably detect the presence of an object, such as a person. In the context of a system, the system includes a sensor configured to emit signals having a predefined wavelength and to detect a reflection of the signals having the predefined wavelength. The system also includes a reflective surface positioned relative to the sensor such that the signals emitted by the sensor are directed toward the reflected surface. The system further includes a filter associated with the reflective surface and positioned relative to the sensor such that the signals emitted by the sensor are also directed toward the filter. The filter is configured to attenuate at least signals having the predefined wavelength.

A well system includes a fiber optic cable positionable downhole along a length of a wellbore. The well system also includes a reflectometer communicatively coupleable to the fiber optic cable. The reflectometer injects optical signals into the fiber optic cable and receives reflected optical signals from the fiber optic cable. Further, the reflectometer identifies strain detected in the reflected optical signals generated from seismic waves of a microseismic event. Additionally, the reflectometer identifies a focal mechanism of the microseismic event and velocities of the seismic waves. The reflectometer also determines a position of the microseismic event using the strain detected in the reflected optical signals, the focal mechanism of the microseismic event, and the velocities of the seismic waves.

In one aspect, an object detection system is provided that adapts to the distance between the emitter and receiver. The system may utilize a range determining operation whereby the receiver will adjust an operation threshold, such as the detected signal strength required for the receiver to indicate that no object is present. The system may increase the threshold of the receiver as the strength of the received signal from the emitter increases, and upon certain conditions, decrease the threshold of the receiver as the strength of the received signal decreases. The system may utilize different receiver thresholds corresponding with different distance ranges between the emitter and receiver. By increasing the threshold of the receiver, the system may disregard low-level reflected light, thereby avoiding ignoring legitimate obstructions, while allowing the system to operate reliably over a wide physical range between the emitter and receiver.

In one aspect, an object detection system is provided that adapts to the distance between the emitter and receiver. The system may utilize a range determining operation whereby the receiver will adjust an operation threshold, such as the detected signal strength required for the receiver to indicate that no object is present. The system may increase the threshold of the receiver as the strength of the received signal from the emitter increases, and upon certain conditions, decrease the threshold of the receiver as the strength of the received signal decreases. The system may utilize different receiver thresholds corresponding with different distance ranges between the emitter and receiver. By increasing the threshold of the receiver, the system may disregard low-level reflected light, thereby avoiding ignoring legitimate obstructions, while allowing the system to operate reliably over a wide physical range between the emitter and receiver.

Described herein is a device for optically surveilling at least one area. The device includes a sender unit and a receiver unit. The sender unit has at least one illumination source. The illumination source is designed to generate at least one light beam having a beam profile. Each light beam is designated for propagating to the receiver unit, thereby traversing at least one area for surveillance. The receiver unit includes at least one transfer device, at least two optical sensors, and at least one evaluation device.

An electromagnetic wave detection apparatus 100 includes a wavelength separator 123 having a transmittance of electromagnetic waves in a first wavelength band larger than a transmittance of electromagnetic waves in a wavelength band other than the first wavelength band, a wavelength selector 124 having a transmittance of electromagnetic waves in a second wavelength band larger than a transmittance of electromagnetic waves in a wavelength band other than the second wavelength band, and a first detector 130 configured to detect electromagnetic waves progressing via the wavelength separator 123 and the wavelength selector 124. The first wavelength band and the second wavelength band partially overlap with each other.

The disclosure provides a small photoelectric sensor that can secure a capacity for accommodating optical components and secure sealing properties. The small photoelectric sensor includes a holder in which an opening, an edge that defines the opening, and four fixing parts that are independently provided at four corners of a front surface are formed on the front surface; a cover lens that is provided at a position interposed between the four fixing parts, and is connected to the edge in a region overlapping the edge; and an optical component that is held by the holder and projects or receives light through the opening.

The disclosure provides a small photoelectric sensor that can secure a capacity for accommodating optical components and secure sealing properties. The small photoelectric sensor includes a holder in which an opening, an edge that defines the opening, and four fixing parts that are independently provided at four corners of a front surface are formed on the front surface; a cover lens that is provided at a position interposed between the four fixing parts, and is connected to the edge in a region overlapping the edge; and an optical component that is held by the holder and projects or receives light through the opening.

Apparatus and associated methods relate to a photoelectric sensor system having a transmitter and a receiver, and at least one aperture module configured to modify a nominal field of view (FOV) of the transmitter and/or receiver, such that an overlap between the transmitter and receiver FOVs is controlled. In an illustrative example, the aperture module may be a plate having respective receiver and transmitter apertures. The transmitter and/or receiver apertures may be aligned or slightly offset from respective transmitter and receiver optical axes. The transmitter and/or receiver apertures may have a specific size/shape/position that produces a custom predetermined FOV overlap. At least one registration/alignment pin may extend through the aperture plate, a baffle, and a lens module to control orientation. The photoelectric sensor system may advantageously (1) be more resistant to the “white card effect,” (2) increase maximum sensor range, and (3) control the shape/size/overlap of the FOVs.