An optical transmission apparatus of an embodiment is an apparatus for redundantly transmitting a multiplexed signal obtained by multiplexing N (N is an integer of 2 or greater) optical signals having different wavelengths, the apparatus including: a first demultiplexing unit to which a first multiplexed signal is input, the first demultiplexing unit configured to demultiplex the input first multiplexed signal into the N optical signals; N first detection units to which the N optical signals demultiplexed by the first demultiplexing unit are respectively input, each of the N first detection units configured to detect presence or absence of deterioration of a corresponding input optical signals of the input optical signals based on a signal level of the corresponding input optical signal; a second demultiplexing unit to which a second multiplexed signal is input, the second demultiplexing unit configured to demultiplex the input second multiplexed signal into the N optical signals; N second detection units to which the N optical signals demultiplexed by the second demultiplexing unit are respectively input, each of the N second detection units configured to detect presence or absence of deterioration of a corresponding input optical signal of the input optical signals based on a signal level of the corresponding input optical signal; and a selection unit configured to select, based on the detection result of presence or absence of deterioration of each of the optical signals by the first detection units and the second detection units, N optical signals having different wavelengths from either the optical signals demultiplexed by the first demultiplexing unit or the optical signals demultiplexed by the second demultiplexing unit.

An optical transmission apparatus of an embodiment is an apparatus for redundantly transmitting a multiplexed signal obtained by multiplexing N (N is an integer of 2 or greater) optical signals having different wavelengths, the apparatus including: a first demultiplexing unit to which a first multiplexed signal is input, the first demultiplexing unit configured to demultiplex the input first multiplexed signal into the N optical signals; N first detection units to which the N optical signals demultiplexed by the first demultiplexing unit are respectively input, each of the N first detection units configured to detect presence or absence of deterioration of a corresponding input optical signals of the input optical signals based on a signal level of the corresponding input optical signal; a second demultiplexing unit to which a second multiplexed signal is input, the second demultiplexing unit configured to demultiplex the input second multiplexed signal into the N optical signals; N second detection units to which the N optical signals demultiplexed by the second demultiplexing unit are respectively input, each of the N second detection units configured to detect presence or absence of deterioration of a corresponding input optical signal of the input optical signals based on a signal level of the corresponding input optical signal; and a selection unit configured to select, based on the detection result of presence or absence of deterioration of each of the optical signals by the first detection units and the second detection units, N optical signals having different wavelengths from either the optical signals demultiplexed by the first demultiplexing unit or the optical signals demultiplexed by the second demultiplexing unit.

Various embodiments are disclosed herein with generally relate to an optical communication system using a photonic lantern. In at least one embodiment, the optical system comprises: an optical transmitter coupled to a signal transmitting path; an optical receiver coupled to a signal receiving path; a photonic lantern, the photonic lantern extending between a first open end and a second open end, the first end comprising an opening to a single multi-mode fiber, and the second end comprising a plurality of single mode fibers that are adiabatically coupled to the multi-mode fiber, the plurality of single-mode fibers includes a single-mode fiber adapted to carry a fundamental optical mode and the remaining single-mode fibers adapted to carry higher-order optical modes, wherein, the single-mode fiber is coupled to the optical transmitting path, the remaining single-mode fibers are coupled to the optical receiving path.

Various embodiments are disclosed herein with generally relate to an optical communication system using a photonic lantern. In at least one embodiment, the optical system comprises: an optical transmitter coupled to a signal transmitting path; an optical receiver coupled to a signal receiving path; a photonic lantern, the photonic lantern extending between a first open end and a second open end, the first end comprising an opening to a single multi-mode fiber, and the second end comprising a plurality of single mode fibers that are adiabatically coupled to the multi-mode fiber, the plurality of single-mode fibers includes a single-mode fiber adapted to carry a fundamental optical mode and the remaining single-mode fibers adapted to carry higher-order optical modes, wherein, the single-mode fiber is coupled to the optical transmitting path, the remaining single-mode fibers are coupled to the optical receiving path.

An optical sensing system includes a transmitter side and a receiver side, and is configured to be positioned below a display of an electronic device. The transmitter side includes a light emitter. The receiver side includes an array of photodiodes. The light emitter of the transmitter side and the array of photodiodes of the receiver side are optically coupled via a waveguide. As a result of this construction, the optical sensing system can be operated as an interferometric optical sensor.

An optical sensing system includes a transmitter side and a receiver side, and is configured to be positioned below a display of an electronic device. The transmitter side includes a light emitter. The receiver side includes an array of photodiodes. The light emitter of the transmitter side and the array of photodiodes of the receiver side are optically coupled via a waveguide. As a result of this construction, the optical sensing system can be operated as an interferometric optical sensor.

A gain adjuster, a gain adjustment method, and an optical line terminal are provided, to separately adjust a gain of a to-be-adjusted optical signal. The gain adjuster includes a light spot conversion component and a gain medium that are sequentially coupled. The gain adjuster further includes a pump laser. The light spot conversion component is configured to adjust light spot sizes of at least some optical signals in received optical signals to output a first optical signal transmitted in space. The pump laser is configured to excite the gain medium. The gain medium is configured to adjust a gain of the first optical signal to output a second optical signal.

A filter includes a first filter component coupled to a second filter component. The first filter component is configured to receive an optical signal, and filter the optical signal based on a first power difference of signals transmitted on a plurality of frequency bands in the optical signal, where the first power difference includes a difference caused by a first doped optical fiber. The second filter component is loaded with a first driving electrical signal used to control a frequency response of the second filter component. The second filter component is configured to filter, using the frequency response based on a second power difference of the signals transmitted on the plurality of frequency bands, an optical signal obtained after the filtering by the first filter component.

Systems and methods for calibrating a Raman amplifier in a photonic line system of an optical network are provided. A method, according to one implementation, includes the step of setting the gain of a plurality of pump lasers of a Raman amplifier to a safe level. For example, the pump lasers are configured to operate at different wavelengths. Also, the Raman amplifier is connected to a fiber span having a specific fiber-type. The safe can be defined as a level that keeps adverse intermodulation effects below a predetermined threshold regardless of the specific fiber-type. In addition, the method includes the step of increasing the gain of the pump lasers without prior knowledge of the specific fiber-type of the fiber span while keeping the adverse intermodulation effects below the predetermined threshold.

An optical signal adjustment unit (1) is configured in such a way that optical signals with different wavelengths are input thereto, and adjusts an intensity of each optical signal based on an intensity change in a transmission line, and outputs the optical signals. A dummy light output unit (2) outputs dummy lights (D) with different wavelengths, each dummy light having an intensity based on an intensity change in a transmission line. A control unit (4) identifies the dummy light corresponding to each optical signal, and controls the intensity of the identified dummy light based on the intensity of the optical signal corresponding to the identified dummy light and output from the optical signal adjustment unit (1). A multiplexing unit (3) outputs a wavelength-multiplexed optical signal (L) where the dummy light (D) and the optical signal (L10) output from the optical signal adjustment unit are combined.