A lens and an optical system device are provided which can measure optical characteristics of a light source or an optical element with a simple structure. A lens 1 has an optical axis, and includes an incident surface F and an emit surface B. The incident surface F and the emit surface B are formed so as to emit incident light to the incident surface F from a first position O at an irradiation angle θ relative to the optical axis from the emit surface B at an emit angle θ/m (where m>1) relative to the optical axis by refraction at the incident surface F and at the emit surface B, and formed in such a way that apparent positions of lights emitted from the emit surface B all begin from a second position P. Moreover, an optical system device includes the lens 1 and a diffuser panel that diffuses emitted light from the lens 1.

A process including the following steps: injecting in an optical fiber a first optical pump at a first optical frequency that evolves in time or not, and a second optical pump at a second optical frequency that evolves in time or not, the first optical frequency and the second optical frequency being different at each given time; a first detection of a first Rayleigh backscattered signal at the first optical frequency from the optical fiber; a second detection, separated from the first detection, of a second Rayleigh backscattered signal at the second optical frequency from the optical fiber; and analyzing the detected first Rayleigh backscattered signal and the detected second Rayleigh backscattered signal.

A receiving apparatus and method for determining transmission characteristics of an optical waveguide in which the receiving apparatus includes a waveguide interface for receiving a mixed light beam having a plurality of modes from a multi-mode optical waveguide and for receiving a blended shifted light beam from the multimode optical waveguide, wherein the mixed light beam has an associated phase for each mode of the plurality of modes, and wherein the mixed shifted light beam has an associated shifted phase for each mode of the plurality of modes; and one or more processors for determining mode information for the intermixed light beam and shifted mode information for the intermixed shifted light beam using a trained neural network and for determining, for each mode of the plurality of modes, the respective associated phase using the intermixed shifted light beam.

An optoelectronic sensor (10) for detecting objects in a monitored zone (20) is provided which has the following: a front screen (38); a light transmitter (12) for transmitting a light beam (16); a movable deflection unit (18) for the periodic sampling of the monitored zone (20) by the light beam (16); a light receiver (26) for generating a received signal from the light beam (22) remitted by the objects; at least one test light transmitter (42); at least one test light transmitter (42), at least one test light receiver (44) and at least one test light reflector (48) which span a test light path (46a-b) through the front screen (38); and an evaluation unit (32) which is configured to acquire pieces of information on the objects in the monitored zone (20) from the received signal and to recognize an impaired light permeability of the front screen (38) from a test light signal which the test light receiver (44) generates from test light which is transmitted from the test light transmitter (42) and which is reflected at the test light reflector (48). In this respect, the test light reflector (48) is arranged such that it moves along with the deflection unit (18).

An optoelectronic sensor (10) for detecting objects in a monitored zone (20) is provided which has the following: a front screen (38); a light transmitter (12) for transmitting a light beam (16); a movable deflection unit (18) for the periodic sampling of the monitored zone (20) by the light beam (16); a light receiver (26) for generating a received signal from the light beam (22) remitted by the objects; at least one test light transmitter (42); at least one test light transmitter (42), at least one test light receiver (44) and at least one test light reflector (48) which span a test light path (46a-b) through the front screen (38); and an evaluation unit (32) which is configured to acquire pieces of information on the objects in the monitored zone (20) from the received signal and to recognize an impaired light permeability of the front screen (38) from a test light signal which the test light receiver (44) generates from test light which is transmitted from the test light transmitter (42) and which is reflected at the test light reflector (48). In this respect, the test light reflector (48) is arranged such that it moves along with the deflection unit (18).

Embodiments of the present invention generally relate to the field of fiber optics, and more specifically to apparatuses, methods, and/or systems associated with testing fiber optic transmitters. In an embodiment, the present invention is an apparatus comprising a laser optimized multimode fiber having near minimally compliant effective modal bandwidth, near maximum channel length, and α-profile that produces an R-MMF DMD slope.

A system and method for performing an in-service optical time domain reflectometry test, an in-service insertion loss test, and an in-service optical frequency domain reflectometry test using a same wavelength as the network communications for point-to-point or point-to-multipoint optical fiber networks while maintaining continuity of network communications are disclosed.

This invention relates to a system and method to determine the distributed birefringence profile along an optical fibre. Birefringence manifests as different refractive indices for two orthogonal states of polarization of the light propagating in the optical fibre. The technique is based on the correlation among sets of measurements acquired using phase-sensitive optical time-domain reflectometry (φOTDR), launching light into the fibre with multiple states of polarization. The correlation between the measurements performed while sweeping the laser frequency gives a resonance (correlation) peak at a frequency detuning that is proportional to the refractive index difference between the two orthogonal polarizations. This enables measurements of the local value of the phase birefringence at any position along the optical fibre, so that longitudinal fluctuations of its value can be evaluated. Such fluctuations can be induced either accidentally during cabling and installation processes, or voluntarily due to varying conditions or environmental quantities such as temperature, strain and pressure, or even unintentionally as a result of a badly controlled manufacturing process.

A system (20) for fiber-optic reflectometry includes an optical source (28, 40), a beat detection module (52, 56) and a processor (36). The optical source is configured to generate an optical interrogation signal that is transmitted into an optical fiber (24). The beat detection module is configured to receive from the optical fiber an optical backscattering signal in response to the optical interrogation signal, and to mix the optical backscattering signal with a reference replica of the optical interrogation signal using In-phase/Quadrature (I/Q) mixing, so as to produce a complex beat signal having In-phase (I) and Quadrature (Q) components. The processor is configured to sense one or more events affecting the optical fiber by analyzing the I and Q components of the complex beat signal.

A system for evaluating the modulation transfer function (MTF) of a device under test is provided. The system includes an image projector configured to provide light in a pattern representing a desired image. The system further includes a lens configured to direct the provided light toward the device under test as a collimated beam. An image analysis component calculates the MTF for the device under test from the at least one image taken at the device under test and the known characteristics of the image projector and the lens.