Bifrost Communications Aps

Danmarks Tekniske Universitet

Technical University of Denmark

Jesper Bevensee Jensen

Bo Pedersen

Roberto Rodes Lopez

Jes Broeng

Jesper Laegsgaard

Bo Petersen

Jose Antonio Altabas Navarro

Lau Frejstrup Suhr

Michele Squartecchia

Guillermo Silva Valdecasa

Kristian Nielsen

Optical systems, receivers, devices, and methods including a free space beam combining and polarization splitting prism to receive local oscillator light and optical signals in substantially parallel input paths that are in the same plane and output two orthogonally polarized beams in substantially parallel output paths that are substantially perpendicular to the plane of the input paths. Light in one of the incoming paths is reflected toward a combining surface that combines the local oscillator light and the optical signal. The combined beam then encounters a polarization splitting surface that splits the combined beam into two orthogonally polarized beams. One of the polarized beam may be reflected 90 degrees in plane and then both orthogonally polarized beams are reflected 90 degrees of out of plane to output each orthogonally polarized beam into substantially parallel optical output paths.

Optical transmission systems, receivers, and devices, and methods of combining and receiving optical signals

Optical systems, devices, and methods are provided for determining various characteristics, such as quantity, movement, distance and speed/velocity of an object relative to the system. The system and method includes an optical transmitter to transmit an output optical signal carrying an electrical reference signal and an optical receiver to receive a reflection of the output optical signal. The receiver includes at least one local oscillator providing local oscillator light at a local oscillator frequency, at least one combiner to combine the reflection of the output optical signal with the local oscillator light into a coupled optical signal. An optical-electrical converter converts the coupled optical signal into a first electrical signal, which is rectified via an envelope detector/rectifier to provide a first rectified electrical signal, which is processed by a signal processor along with the reference signal to calculate various characteristics of an object that reflected the output optical signal, such as the quantity, movement, distance, velocity, etc.

Optical systems, devices, and methods including high performance optical receivers

Optical receivers including at least one local oscillator providing local oscillator light at a local oscillator center frequency offset from a received optical signal by a frequency difference. A combiner for combining the optical signal with the local oscillator light and to output at least one combined optical signal. An opto-electrical converter down-converts the combined optical signal into corresponding RF electrical signal at the frequency of the frequency difference. A filter may be provided to at least substantially remove one of the upper and lower electrical signal sidebands to output one of a VSB and SSB RF signal before rectification. A local oscillator frequency controller may adjustably control the local oscillator frequency to provide the difference frequency that produces a specified group delay in the RF electrical signal that may be specified via optical receiver performance parameters and/or user input and offset using a group delay filter.

Optical transmission systems, receivers, and devices, and methods of receiving optical signals

The present invention relates to communication systems, devices, and methods for providing for a wide bandwidth optical receiver including amplification through optical beating from a local oscillator laser operating without a phase-locked loop at frequency near the receiver optical signal and decreasing the system-performances dependence on optical polarization alignment between the signal and the local oscillator. Systems, devices, and methods including a local oscillator providing a local oscillator signal having a local oscillator frequency that may be controlled based on a frequency offset from the signal center frequency through the use of monitoring signals representative of the frequency offset. A combiner/splitter couples the optical data signal with light from the local oscillator to provide first and second coupled optical signals with orthogonal polarization. Two opto-electrical converters for converting first and second coupled signals into first and second electrical signals. The first and second electrical signals are individually rectified and then combined to provide the electrical data signal. The opto-electronic converters and rectifiers may have a bandwidth substantially similar the wavelength channel bandwidth to enable the optical receiver to receive optical signal with different center frequencies within the wavelength channel.

Optical communication systems, devices, and methods including high performance optical receivers

The present disclosure relates to a method for decoding a combined AM/FM encoded signal, comprising the steps of: combining said encoded optical signal with light from a local oscillator configured with a local oscillator frequency; converting the combined local oscillator and encoded optical signal into one or more electrical signals by means of at least one opto-electrical converter having a predefined frequency bandwidth, thereby providing an amplified and encoded electrical signal having one or more encoded signal current(s), where one type of states have a higher oscillation frequency than other type of states; rectifying the encoded signal current(s), thereby obtaining an encoded power spectrum, wherein said power spectrum has different states, such as '0'-states and '1'-states, with different power levels such that they can be discriminated, said local oscillator frequency is defined by a positive local oscillator frequency-offset from the frequency of one of the states in said encoded optical signal, and said local oscillator frequency-offset is selected to be dependent on said frequency bandwidth.

Decoding a combined amplitude modulated and frequency modulated signal

The present disclosure relates to system applications of multicore optical fibers. One embodiment relates to a base transceiver station for a wireless telecommunication system comprising a plurality of antenna units arranged in a MIMO configuration and adapted for transmission and/or reception of radio-frequency signals, an optical transmitter in the form of an electro-optic conversion unit for each of said plurality of antenna units, each electro-optic conversion unit adapted for converting an RF signal into an optical signal, a plurality of a single core optical fibers for guiding the optical signals, and at least one first space division multiplexing (SDM) unit adapted for multiplexing said single core optical fibers into respective individual cores of a multicore fiber, or into respective individual modes of a multimode fiber.

Growing community of inventors

Albertslund, Denmark

Jesper Bevensee Jensen