Directional wireless drop systems are provided. These systems include a tap unit that is connected to a communications line of the broadband network; a cable modem unit connected to the tap unit; a plurality of wireless routers connected to the cable modem unit; and a directional antenna unit that is connected to at least a first of the wireless routers. Each wireless router is associated with a respective one of a plurality of subscriber premises that are served by the directional wireless drop system and is configured to communicate with at least one device that is located at the respective one of plurality of subscriber premises.

Directional wireless drop systems are provided. These systems include a tap unit that is connected to a communications line of the broadband network; a cable modem unit connected to the tap unit; a plurality of wireless routers connected to the cable modem unit; and a directional antenna unit that is connected to at least a first of the wireless routers. Each wireless router is associated with a respective one of a plurality of subscriber premises that are served by the directional wireless drop system and is configured to communicate with at least one device that is located at the respective one of plurality of subscriber premises.

An RF transmitter comprising an optical source configured to generate a pair of optical lines separated by an RF carrier frequency. The transmitter may comprise a graphene photodetector having at least two electrical contacts; a transmit antenna coupled to a first of the electrical contacts; and an electrical data signal input connected to a second of the electrical contacts. The graphene photodetector is illuminated by the optical source; it may comprise a graphene photo-thermal effect (PTE) photodetector or a bolometric photodetector. A corresponding receiver is also described.

An RF transmitter comprising an optical source configured to generate a pair of optical lines separated by an RF carrier frequency. The transmitter may comprise a graphene photodetector having at least two electrical contacts; a transmit antenna coupled to a first of the electrical contacts; and an electrical data signal input connected to a second of the electrical contacts. The graphene photodetector is illuminated by the optical source; it may comprise a graphene photo-thermal effect (PTE) photodetector or a bolometric photodetector. A corresponding receiver is also described.

The purpose of the present invention is to provide a device for optical frequency domain reflectometry and a method thereof that can measure a reflectance distribution with less spatial resolution degradation due to a phase noise, without using a wideband receiving system even when a long-distance measurement is performed. The device for optical frequency domain reflectometry according to the present invention is provided with a delay optical fiber for delaying a local light by a prescribed time, and obtains information on a relative delay of a backscattered light from an optical fiber under measurement with respect to the local light and information on the positivity and the negativity of a beat frequency by measuring an in-phase component and a quadrature component of a beat signal obtained by multiplexing the backscattered light from the optical fiber under measurement and the local light delayed by the delay optical fiber, so as to obtain a reflectance distribution in a longitudinal direction of the optical fiber under measurement based on these pieces of information.

An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

A LiDAR system includes an optical source for generating a continuous wave (CW) optical signal. A control processor generates a pulse-position modulation (PPM) signal, and an amplitude modulation (AM) modulator generates a pulse-position amplitude-modulated optical signal, which is transmitted through a transmit optical element into a region. A receive optical element receives reflected versions of the pulse-position amplitude-modulated optical signal reflected from at least one target object in the region. An optical detector generates a first baseband signal. A signal processor receives the first baseband signal and processes the first baseband signal to generate an indication related to a target object in the region.

A LiDAR system includes an optical source for generating a continuous wave (CW) optical signal. A control processor generates a pulse-position modulation (PPM) signal, and an amplitude modulation (AM) modulator generates a pulse-position amplitude-modulated optical signal, which is transmitted through a transmit optical element into a region. A receive optical element receives reflected versions of the pulse-position amplitude-modulated optical signal reflected from at least one target object in the region. An optical detector generates a first baseband signal. A signal processor receives the first baseband signal and processes the first baseband signal to generate an indication related to a target object in the region.

Methods, systems, and devices for network communications to reduce optical beat interference (OBI) in upstream communications are described. For example, a fiber node may provide a seed source to injection lock upstream laser diodes. Therefore, upstream communications from each injection locked laser diode may primarily include the wavelength associated with each seed source. The seed sources may be unique to each end device and configured to minimize OBI. That is, the upstream laser diodes may be generic, but the collected seed source may enable upstream communications at varying wavelengths. The end device may provide upstream communications by externally modulating a signal generated by the injection locked laser diode.