Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprise cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining.

A device includes a multiple-wavelength (e.g., dual wavelength) vertical-cavity surface-emitting laser (VCSEL) array including a first VCSEL set including one or more first VCSEL to emit first VCSEL radiation at a first wavelength, and a second VCSEL set including one or more second VCSEL to emit second VCSEL radiation at a second wavelength different than the first wavelength. The device includes upstream optics to upstream optics to (a) collimate the first VCSEL radiation emitted by the first VCSEL set and (b) collimate the second VCSEL radiation emitted by the second VCSEL set. The device also includes a vapor cell to receive the collimated first VCSEL radiation and the collimated second VCSEL radiation and to provide an output beam as a function of the received collimated first VCSEL radiation and collimated second VCSEL radiation, and measurement circuitry to analyze the output beam provided by the vapor cell.

A broadband laser system enhanced in the later part of mid infrared spectrum is provided, which can obtain a high power and wide spectrum laser output enhanced in the later part of mid infrared spectrum, and has the advantages of full fiber, compact structure and high ratio of power in the later part of mid infrared spectrum. It includes a mode-locked fiber laser, a pre amplifier, an optical fiber stretcher, an amplifier, a main amplifier, a first nonlinear optical fiber, a mid infrared amplifier and a second nonlinear optical fiber, which are connected in sequence, and each of them adopts a water cooling device or a thermo electric cooler, and is connected by optical fiber fusion.

Embodiments of the present disclosure may comprise an optical amplifier system, the system comprising an erbium-doped fiber amplifier. Embodiments may also comprise a C-band amplified spontaneous emission stage configured to generate C-band light. Embodiments may also comprise an L-band stage configured to generate L-Band light. Embodiments may also comprise a Raman amplifier comprising a fiber span. In accordance with various embodiments, the Raman amplifier may be pumped using a portion of the generated C-band light.

An apparatus is provided to receive a three dimensional (3D) map of at least a part of a body of a user. A light emitting device is included with tunable VCSEL laser with one or more active regions having quantum wells and barriers. The active regions are surrounded by one or more p-n junctions. The one or more active regions can include a selected shape structure one or more tunnel junction (TJ) 20s provided. One or more apertures are provided with the selected shape structure. One or more buried tunnel junctions (BTJ) or oxide confine the apertures, additional TJ's, planar structures and or additional BTJ's created during a regrowth process that is independent of a first growth process. A VCSEL output is determined in response to an application of the VCSEL laser. The VCSEL laser includes an HCG grating and a bottom DBR. A user monitoring device 100 includes the VCSEL laser. A user monitoring device that includes the VCSEL laser 10. The light emitting device is included in a camera of a communication device.

Disclosed are an ultrafast electric pulse generation and detection device and a use method thereof. The device includes a laser and an electric pulse generator. The electric pulse generator includes: a photoelectric material layer including an optically controlled switching region for responding to excitation light generated by the laser; an insulating layer formed on the photoelectric material layer, wherein a switch structure exists at a position of the insulating layer corresponding to the optically controlled switching region, so that the optically controlled switching region is partially exposed or completely exposed; transmission lines are formed on the insulating layer.

According to an aspect of an embodiment, an erbium doped fiber amplifier (EDFA) may include a first EDFA stage configured to amplify a first wavelength range, a second wavelength range, and a third wavelength range. The EDFA may also include a filter stage configured to receive optical signals amplified by the first EDFA stage and attenuate the second wavelength range less than a gain applied to the second wavelength range by the first EDFA stage. In addition, the EDFA may include a second EDFA stage configured to receive the optical signals after the optical signals have passed through the filter stage. The second EDFA stage may also be configured to amplify the first wavelength range, the second wavelength range, and the third wavelength range.

Wavelength-tunable source of pulsed laser radiation for VIS-NIR spectroscopy which consists of a pump source (1) forming bursts of picosecond pulses of high pulse repetition rate, and a synchronously pumped optical parametric oscillator (2). The pump source (1) comprises a solid-state regenerative amplifier (31) having one or two electro-optical switches (32,33) inside its resonator (44). The switches create partial transmission of the resonator for a time interval longer than a resonator roundtrip time, and eject a part of energy of a pulse circulating inside. Bursts of 5-10 ns duration are formed, which are filled with high peak power picosecond pulses. Pulse repetition rate of the order of GHz of pump pulses allows the construction of a compact optical parametric oscillator. The whole set of parameters ensures high energy efficiency, stability and an ability to provide output pulse bursts repeating at up to 10 kHz repetition rate.

A power amplifier module (PAM) includes an input that receives a first beam at a signal wavelength (.sub.s) from a seeder laser source (SLS) which includes previous stages of a multi-stage fiber-based optical amplifier chain. The PAM includes an optical pump laser (OPL) that generates an optical pump beam at a pump wavelength (.sub.p). The PAM includes a fiber-optic output configured to fusion splice to a large-core rare-earth doped power amplifier fiber (PAF). The PAM includes a wavelength-division-multiplexer (WDM) configured to spectrally combine the first beam with the optical pump beam into a single combined beam that the WDM outputs into a core of the PAF via the fiber-optic output. The .sub.p is an in-band wavelength at which the optical pump beam emitted by the OPL optically pumps the core such that the PAF, in response to receiving the combined beam, emits an output beam at wavelength>2 m.

A laser assembly, including a first CW laser having a first fiber optic cable operationally connected thereto for directing a first CW laser output, a second QCW laser having a second fiber optic cable operationally connected thereto for directing a second QCW laser output, and a third Q-switched laser having a third fiber optic cable operationally connected thereto for directing a third Q-switched laser output. A fusion point is operationally connected to the first, second, and third fiber optic cables for combining the first, second, and third laser outputs into a composite output. A fourth fiber optic cable is connected to and extends from the fusion point for directing the composite output.