An optical fiber amplifier compatible with a small form-factor pluggables (SFP+) package includes a housing, and a circuit device and an optical path device that are disposed in the housing, where the housing includes a structure compatible with an SFP+ package and is provided with an accommodation space; both the circuit device and the optical path device are located in the accommodation space, and the optical path device is located below the circuit device; the circuit device is provided with a card edge connector, and the card edge connector can be exposed outside the housing. The optical fiber amplifier compatible with an SFP+ package has a compact internal space. The amplifer has an appearance compatible with a standard SFP+ package. An electrical interface pin also meets a requirement of an existing SFP+ package, and dynamic plugging and plug-and-play can be satisfied.

Embodiments relate to a polymer waveguide including a substrate, a cladding layer made of a first polymer, formed on the substrate, wherein a first monomer is polymerized into the first polymer, and the cladding layer has a groove for the waveguide by removing part of the cladding layer, and a core accommodating graphene therein, formed on the groove, a method for manufacturing the same, and a passively mode-locked laser based on the polymer waveguide.

To provide a mode-locked pulse photoproduction filter for easily realizing self-starting mode-locking, and a laser device for generating a picosecond or femtosecond-pulse laser light by including such filter, the laser device including an amplifying unit for amplifying and outputting a light inside a resonator, and the mode-locked pulse photoproduction filter having a first filter part for selectively outputting a first wavelength component that is a wavelength component of an oscillation band inside the resonator, and a second filter part for selectively outputting a second wavelength component that is a wavelength component different from the oscillation band inside the resonator.

An electrically tunable non-reciprocal phase shifter, an electrically tunable polarization filter, a NALM mode-locked laser and a Sagnac loop are provided. The electrically tunable non-reciprocal phase shifter includes a modulation crystal device, a birefringent crystal device, a Faraday rotator, and a fiber coupler. The phase shifter is configured to couple two beams of light to a fast axis and a slow axis of the modulation crystal device, respectively; and change a refractive index difference between the fast axis and the slow axis to introduce different phase delays for the two beams of the light, so as to control a non-reciprocal linear phase shift amount between the two beams of the light.

A macroscopic entanglement state in which a polarization state has a strong quantum correlation is realized by use of a macroscopic laser light. A laser oscillator includes a ring resonator having an optical fiber ring, an optical amplifier for maintaining an amplitude of a laser pulsed light propagating on the optical fiber ring, and three optical fibers that are connected with respective polarization controllers, and, after changing a polarization state of the laser pulsed light being a qubit extracted at a predetermined branch ratio from the optical fiber ring by the polarization controllers, couples the changed laser pulsed light whose polarization state has been changed with the laser pulsed light propagating on the optical fiber ring, and each polarization controller rotates the polarization state of the laser pulsed light with an S1 axis, an S2 axis, and an S3 axis, which are orthogonal to each other, as a rotation axis.

Photonic chip includes an external cavity (EC) optical circuit to provide wavelength-selective optical feedback to a length of active optical fiber. Light generated in the active optical fiber may be coupled from the EC circuit to a light processing circuit of the photonic chip, such as an optical modulator or an optical mixer. The EC circuits may include single-frequency and multi-frequency optical filters, which may include ring resonators, dual-ring resonators, and optical modulators to support multi-frequency lasers. The EC circuits may further include pump combiners and optical isolators.

One or more embodiments relates to a system for simultaneously detecting vibration and the presence of a target gas having a tunable fiber ring laser in electronic and optical communication with a vibration sensor and a gas detection sensor. One or more embodiments relate to a method for simultaneously measuring vibration and detecting the presence of a target gas in an environment having the steps of providing a system for simultaneously measuring vibration and detecting a target gas into an environment; sending an optical signal to a vibration sensor and gas detection sensor; and collecting and analyzing modified signals from the vibration sensor and gas detection sensor.

There is described a fiber laser system generally having a pump laser generating a pump laser beam; and a length of optical fiber optically coupled to the pump laser, the length of optical fiber having: a laser cavity having a cavity path, a first fiber Bragg grating having a first reflectivity profile, a second filter having a second filter profile, and an optical gain region between the first fiber Bragg grating and the second filter along the cavity path, the first reflectivity profile being spectrally detuned from the second filter profile, the first fiber Bragg grating having a first refractive index profile comprising a full width at half maximum bandwidth of at least 0.2 nm and a Gaussian-like apodization, wherein, upon pumping of the optical gain region with the pump laser beam and mode locking of the laser cavity, optical pulses are circulated along the cavity path; and an output.

A bidirectional mode-locked fiber laser includes first and second passive optical fibers, a doped optical fiber, first and second polarization controllers, and first and second polarized beamsplitters that are arranged as a ring cavity with clockwise (CW) and counter-clockwise (CCW) directions. The laser imparts different nonlinear phase shifts in the CW and CCW directions, corresponding to CW and CCW repetition rates that are slightly different. When the normalized difference in repetition rates is less than approximately 10.sup.−5, both directions can be mode-locked simultaneously, thereby preventing one direction from inhibiting mode-locking of the other direction. Optical-fiber nonlinearity implements an intra-cavity bidirectional artificial saturable absorber based on nonlinear polarization rotation. The laser uses only components with normal group-velocity dispersion (GVD), thereby achieving higher pulse energies than mode-locked lasers utilizing negative GVD. The combination of artificial saturable absorber and normal GVD components increases pulse energy, which improves the efficiency of spectral broadening.

A high-precision repetition rate locking apparatus for an ultra-fast laser pulse includes: an electronic controlling component comprising: a standard clock, configured to provide a high-precision frequency standard; a pulse generator (PG), configured to provide an electrical pulse signal with adjustable repetition rate, pulse width and voltage magnitude; and a signal generator (SG), connected to the standard clock and the PG, and configured to provide a stable frequency signal for the PG, a phase-shift adjusting component, connected to the electronic controlling component and configured to implement phase modulation through electrically induced refractive index change; a resonant cavity component, comprising a phase shifter, a doped fiber, a laser diode, a wavelength division multiplexer and a reflector, and configured to generate a mode-locked pulse; and a detection system, configured to measure a repetition rate of an output pulse.