Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery system, comprising an optical fiber including a first length of fiber comprising a first RIP formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof and a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within one or more first confinement regions. The optical beam delivery system may include an optical system coupled to the second length of fiber including one or more free-space optics configured to receive and transmit an optical beam comprising the modified one or more beam characteristics.

The present disclosure relates to methods and apparatuses for providing optical radiation having improved rise/fall times and improved levels of leakage. One method for amplifying optical radiation includes an intermediate stage (220) having an intermediate active optical fiber (222), the intermediate active optical fiber and a final amplifying stage (230) including a final active optical fiber (232), and providing optical radiation to the input of the intermediate active optical fiber, wherein one or more final optical pump sources (235) are together in a low power state such that the optical radiation is substantially absorbed by the intermediate active optical fiber and such that substantially no optical radiation of the amplified wavelength is transmitted by the intermediate stage. The intermediate active optical fiber (222) can then be switched to a transmissive state by switching the final optical pump source(s) (235) to a high power state. The input to the intermediate stage may comprise a seed laser (205) and plural first amplifier stages (210) having each a first active optical fiber (212). A filter (260) between the intermediate stage (220) and the final amplifying stage (230) prevents ASE and pump light from the intermediate stage to reach the final amplifying stage.

A system and methods for providing optical, downhole data communication without requiring a light source in the downhole tool is disclosed. A carrier signal generated at the surface is sent to the downhole tool using an optical fiber. An optical modulator of the downhole tool uses data signals from a sensor to modulate the carrier signal based on the data signals. The modulated signal is transmitted to one or more optical receivers. The optical modulator can be coupled to the one or more optical receivers through the same optical fiber as the carrier signal generator, or one or more additional optical fibers.

A light emitting element array includes plural semiconductor stacking structures and a light screening portion. The plural semiconductor stacking structures each include a light emitting portion and a light receiving portion that receives light propagated in a lateral direction via a semiconductor layer from the light emitting portion. The light screening portion is provided between the plural semiconductor stacking structures to screen light directed from the light emitting portion of one of the semiconductor stacking structures to the light receiving portion of another semiconductor stacking structure.

An arrayed waveguide grating multiplexer/demultiplexer includes an array of optical waveguides ordered in sequence from a shortest waveguide up to a longest waveguide, and identical phase shifters configured to be controlled by a same control signal. Each phase shifter increases/decreases an optical path of an optical waveguide by the same quantity based on the control control signal.

Preparation cell systems and methods are described herein. One example of a system for a preparation cell includes a laser coupled to a fiber bundle comprising a plurality of fibers, a preparation cell to prepare a state of laser light received by the fiber bundle, and an exiting fiber bundle coupled to the preparation cell.

In a multi-pulse light source, a dispersion compensation unit includes a spectroscopic element configured to spectrally separate a plurality of wavelength components, a separation optical element that guides a first optical pulse group including one or more wavelength components among a plurality of wavelength components, and a second optical pulse group including one or more wavelength components different from the one or more wavelength components included in the first optical pulse group among the plurality of wavelength components to optical paths different from each other, a first spatial light modulator on which the first optical pulse group is incident and which compensates dispersion for each wavelength component with respect to the first optical pulse group, and a second spatial light modulator on which the second optical pulse group is incident and which compensates dispersion for each wavelength component with respect to the second optical pulse group.

A method for reducing interference from scattered light/reflected light of an interference path by generating carrier through phase. Phase modulation is applied on the terminal of a fiber path, and a target signal is separated from an interference signal by selecting a specific working point, to obtain a purer target signal, thereby lengthening the measurement distance. The signal demodulation manner used in this method is different from the traditional manner of modulation performed by generating a carrier through the phase, and does not need to use the modulation frequency as the reference signal during demodulation, so this manner is easily implemented. The method is applicable to long-distance pipeline monitoring and wide-range fiber perimeter security, and especially to an application environment in which the modulation end is far away from the signal demodulation end. The method can also be applied in an application in which measurement is implemented by modulating an optical transmission phase in a feedback device.

Preparation cell systems and methods are described herein. One example of a system for a preparation cell includes a laser coupled to a fiber bundle comprising a plurality of fibers, a preparation cell to prepare a state of laser light received by the fiber bundle, and an exiting fiber bundle coupled to the preparation cell.

Systems, apparatuses, and methods for modulating light at high frequencies by addressing the issue of direct modulation of long lifetime light emitters. Dynamic control of the local density of optical states (LDOS) to exploit the differences between electric and magnetic dipole transitions allows for higher frequency modulation. The LDOS is controlled, in part, by designing a structure such that it enhances or suppresses electric and magnetic dipoles. Direct modulation may be achieved by designing the optical environment to adjust the interferences between the emitted light field and its own reflection at the emitter's location. The optical environment may include light emission material, switchable material, spacer materials, and reflective materials. The structures creating the optical environment enable a new nanometer-scale architecture for on-chip ultrafast directly modulated light sources, which could be easily integrated locally on a range of nanoelectronic and nanophotonic structures, along with light-emitting diodes, waveguides, and fiber optics.