Massachusetts Institute of Technology

Juan Montoya

Antonio Sanchez-Rubio

Peter Colin Reeves-Hall

Dale G Fried

Dale H Martz

Richard M Heinrichs

Harold C Payson

Robert E Hatch

Steven Jay Spector

Tso Yee Fan

Caroline Anne Ross

Steven J Augst

Reuel Bennett Swint

Daniel J Ripin

Christopher Aleshire

A photonic lantern couples light from several fibers or fiber cores into one or more fibers or fiber cores. Photonic lanterns are often used to combine several lower-power beams into a single higher-power beam. They can also be used to couple light from multi-core fibers into single-mode, multi-mode, or other multi-core fibers. By modulating the phases of the input beams, the light can be switched from output to output&#x2014;for example, between output cores of a multi-core output fiber. If desired, the beams can also be amplified using an active fiber in or coupled to the photonic lantern. A first photonic lantern couples signal light and pump light into the core and cladding, respectively, of an active multi-mode or multi-core fiber. And the active multi-mode or multi-core fiber couples amplified signal light into output fiber(s) via a second photonic lantern.

Photonic lantern structures and devices

An electro-optic beam controller, material processing apparatus, or optical amplifier, and corresponding methods, can include an actively controlled, waveguide-based, optical spatial mode conversion device. The conversion device can include a coupler, which can be a photonic lantern, configured to combine light beams into a common light beam; a sensor configured to measure at least one characteristic of the common light beam; and a controller configured to modulate optical parameters of the individual, respective light beams to set one or more spatial modes of the common light beam. Actively controlled and modulated devices can be used to maintain a stable, diffraction-limited beam for use in an amplification, communications, imaging, laser radar, switching, or laser material processing system. Embodiments can also be used to maintain a fundamental or other spatial mode in an optical fiber even while scaling to kilowatt power.

Electro-Optic beam controller and method

A method of imaging a scene includes generating a temporally varying optical intensity pattern from at least one continuous wave (CW) light beam. The method also includes illuminating at least one portion of the scene with the temporally varying optical intensity pattern so as to cause a photon to scatter or reflect off the at least one portion of the scene. The photon reflected or scatted from the at least one portion of the scene is detected using a single-photon detector. Based on the temporally varying optical intensity pattern and a time of flight of the photon detected, a distance between the single-photon detector and the at least one portion of the scene is estimated.

Methods and apparatus for phased array imaging

Coherent beam combining of laser gain elements achieves high output power in a diffraction limited beam. An active beam combining system coherently combines optical beams emitted by semiconductor laser gain elements in an external resonant cavity configuration. A beam combiner in the resonant cavity combines the outputs of the laser gain elements into a single coherent output beam whose power is monitored by a photodetector. A processor uses the photodetector's output to adjust the phases of the respective optical beams emitted by the laser gain elements so as to increase or maximize the coherent output beam's power. The processor may vary the optical beams' phases according to a stochastic parallel gradient descent (SPGD) algorithm for active phase control. Experimental results show a beam combining efficiency of 81% with an upper limit of 90% or higher and without the scaling limits imposed on passive-phasing systems.

Methods, systems, and apparatus for coherent beam combining

An optical structure for generating nonreciprocal loss is provided that includes a first substrate layer and a magneto-optical layer positioned on the first substrate layer. The magneto-optical layer achieves nonreciprocity with application of an external magnetic field so as to produce resonantly enhanced nonreciprocal loss.

On-chip miniature optical isolator

Growing community of inventors

Belmont, MA, United States of America

Juan Montoya