Florida Institute of Technology

Other

Harris Corporation

Syed H Murshid

Bilas Chowdhury

Han Wang

Barry G Grossman

Rayan Enaya

Engin Eyceyurt

Puntada Narakorn

Greg Lovell

Ce Su

Raymond Charles Rumpf

Gregory L Lovell

Michael F Finch

Azhar M Khayrattee

Saud Alanzi

A modified optical PAM communication system using multiple laser sources to generate each amplitude level. The systems can be applied separately or in conjunction with another modulation system such as SDM, MDM, WDM, TDM, or other communication systems. In an embodiment, a PAM-4 system will increase data rate by a factor of two, but more complicated schemes using more lasers can be utilized to generate higher efficiency schemes. For example, a 25 Gbps NRZ signal will give 50 Gbps PAM-4 signal and higher laser systems can generate PAM-8 or PAM-16 for 75 and 100 Gbps systems respectively. These can be further applied to SDM systems to generate higher data rates equivalent to the number of SDM channels multiplied by the PAM efficiency. In embodiments, the invention may combing PAM with WDM and SDM to achieve multiple bits per symbol.

System for achieving multiple bits per symbol in optical communications systems by combining spatial domain multiplexing and pulse amplitude modulation

A multiplexed optical communication system comprising a carrier optical fiber, a plurality of launching light sources, and a matching plurality of multiplexer/demultiplexers and photodetectors is described and claimed. Optical communication channel separation by Spatial Domain Multiplexing (SDM), Optical Angular Momentum (OAM) multiplexing, and Wavelength Division Multiplexing (WDM) is used in combination to achieve significant increase in optical communication channel bandwidth over the prior art. The launching light sources may be positioned such that the light beams are incident on the receiving end of the carrier optical fiber at desired angles including complementary angles. Crosstalk between optical communication channels is minimal. The communication bandwidth of a TDM system may be increased by an order of magnitude due the layered WDM/SDM/OAM data multiplexing of the invention.

Method and apparatus for multiplexed optical communication system using spatial domain multiplexing (SDM) and orbital angular momentum of photon (OAM) multiplexing with wavelength division multiplexing (WDM)

An optical-to-optical inline spatial domain multiplexing (SDM) de-multiplexer for SDM communication comprising a plurality of concentric core layers each having a beveled output end and a cladding layer concentrically surrounding each core layer. The cladding layer has an index that is lower than the index of the core layer it surrounds. Also included is a system for SDM communication comprising at least one optical source to transmit optical energy, an SDM optical carrier fiber to receive optical energy from the source and output a plurality of SDM signals, a SDM de-multiplexer as described above wherein the SDM signals output from the carrier fiber are each incident upon one of the core layers, optical output fibers positioned to couple SDM signals from each cladding layer, and a photodetector communicatively coupled to the outputs of the optical output fibers to couple the SDM signals output from the optical output fibers.

All-optical spatial domain multiplexing de-multiplexer

A free space optical receiver comprising a photodetector and a fiber bundle. The fiber bundle comprises a plurality of optical fibers splayed apart at one of their ends to receive free space optical energy from multiple directions. The splayed apart ends of the plurality of optical fibers may create a hemispherical shape. Each of the plurality of optical fibers has an acceptance cone for which it couples optical energy into the splayed end of the optical fiber. The acceptance cones of the splayed ends of the plurality of optical fibers may overlap to form an omnidirectional acceptance zone. The other, non-splayed ends of the plurality of optical fibers are communicatively coupled to the photodetector, which is positioned to receive the free space optical energy from the non-splayed ends of the plurality of optical fibers. An optical communication system including the free space optical receiver is also described.

Omnidirectional free space optical communications receiver

Multiple light beams are launched into a single optical fiber, each respective light beam with a corresponding signal. Each of the respective multi-beams are separated by launching each of the light at a different incidence angle and/or input position, into the optical fiber. In this way, each light beam is able to propagate independently according to its own trajectory inside the fiber. The resultant multi light beams propagate with respective counter cyclical orbital angular momentum with respective helical paths.

Orbital angular momentum in spatially multiplexed optical fiber communications

An octagonal structure of photodiodes using standard CMOS technology has been developed to serve as a de-multiplexer for spatially multiplexed fiber optic communication systems.

Array of concentric CMOS photodiodes for detection and de-multiplexing of spatially modulated optical channels

The subject invention pertains to a method and apparatus for multiplexing in optical fiber communications. The subject invention relates to a method and apparatus for spatial domain modulation in optical wavelengths. In a specific embodiment, the subject invention relates to a spatial domain multiplexer (SDM) for use with an optical fiber. Preferably, the input channels coupled into the fiber optic cable include collimated laser beams. The techniques of the subject invention can be utilized with single mode and multi mode waveguide structures, for example, single mode and multi mode optical fibers. The subject invention is applicable to step index optical fiber and to graded index optical fiber. Applications of the subject technology can include secure data links, for example, which can modulate data such that if the data is intercepted, the data cannot be interpreted. The subject methods and apparatus can also be used in conjunction with other multiplexing techniques such as time-domain multiplexing.

Method and apparatus for spatial domain multiplexing in optical fiber communications

The method for making the fiber optic Fabry-Perot sensor includes securing an optical fiber to a substrate, and forming at least one gap in the optical fiber after the optical fiber is secured to the substrate to define at least one pair of self-aligned opposing spaced apart optical fiber end faces for the Fabry-Perot sensor. Preferably, an adhesive directly secures the at least one pair of optical fiber portions to the substrate. The opposing spaced apart optical fiber end faces are self-aligned because the pair of optical fiber end portions are formed from a single fiber which has been directly secured to the substrate. Also, each of the self-aligned spaced apart optical fiber end faces may be substantially rounded due to an electrical discharge used to form the gap. This results in integral lenses being formed as the end faces of the fiber portions.

Fiber optic Fabry-Perot interferometer and associated methods

A fiber optic liquid level detector uses optical fibers to detect the presence or absence of liquids. The waveguide properties of optical fibers tends to deviate from the normal dielectric interfaces so that a fiber immersed in a liquid has a reflection coefficient smaller than when surrounded by air. This is caused by the differences in refractive indices of liquid and air and is used to measure the amount of light transmitted or reflected by the fiber in the preserve or absence of a liquid.

Growing community of inventors

Palm Bay, FL, United States of America

Syed H Murshid