An amplified spontaneous emission (ASE) source is proposed for use as a pump for fiber-based optical amplifiers and lasers. It is proposed to the ASE source in place of the conventional single-wavelength pump source. The ASE pump power can be generated using a simpler configuration than a conventional fiber-based laser source. Advantageously, it has been found that an ASE source of pump light may be as efficient as the conventional single-wavelength pump source in many applications. Furthermore, given the relatively high levels of pump power required for some applications, ASE pumping is thought to reduce the possibility that fiber nonlinearities (e.g., stimulated Brillouin scattering or Raman scattering) are triggered in the gain fiber.

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.

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.

An erbium fiber laser produces a beam of ultrashort laser pulses having a center wavelength greater than 780 nanometers, an average power greater than 0.5 watt, and a spectral bandwidth compressible to a pulse duration of less than 200 femtoseconds. The laser includes a fiber preamplifier that is energized by a counter-propagating pump beam, has relatively low population inversion in a relatively long optical gain fiber, and provides a spectrally-shaped beam for further amplification. Wavelength dependent gain and absorption within the optical gain fiber enhances longer wavelengths relative to shorter wavelengths in the spectrally-shaped beam. The spectral shaping is sufficient to overcome gain narrowing and gain shifting in a subsequent high-gain fiber amplifier.

A low wavelength infrared Super Continuum (SC) signal from a master oscillator introduces two or more seeds into an amplifier that supports the Raman effect. A counter-propagating, high-power, continuous wave, or quasi-continuous wave quantum cascade lasers pump (amplifies) a first optical seed creating a cascading amplification of subsequent optical seeds forming two or more tunable wavelength coherent optical pump sources.

The present invention provides a blue laser transmitter operating at the H-beta Fraunhofer line at 486.13 nm wavelength. The subject blue laser is based on pulsed lasing action in thulium doped into lutetium sesquioxide (Tm:Lu.sub.2O.sub.3). The laser wavelength is restricted by volume Bragg grating to the vicinity of 1944 nm wavelength. The laser is operated with a q-switch to generate high-energy pulses within the nanosecond regime. The output at the 1944 nm wavelength is then frequency quadrupled in a single pass through non-linear crystals to a wavelength near the center of the H-beta Fraunhofer line. The operation at the 1944 nm wavelength in Tm:Lu.sub.2O.sub.3 is very efficient because this wavelength is located on a shoulder of a substantially broad emission peak at 1945 nm. In addition, at the 1944 nm wavelength, Tm:Lu.sub.2O.sub.3 has only a modest saturation fluence of about 15 J/cm.sup.2, which allows for efficient energy extraction.