A broadband optical amplifier for operation in the 2 μm visible wavelength band is based upon a single-clad Tm-doped fiber amplifier (TDFA). A compact pump source uses a combination of low-power laser diode with a fiber laser to provide a multi-watt pump beam without needing to include thermal management and/or pump wavelength stability components. The broadband optical amplifier is therefore able to be relatively compact device with fiber coupled output powers of >0.5 W CW, high small signal gain, low noise figure, and large OSNR, important for use as a versatile wideband preamplifier or power booster amplifier.

A method for fabricating a light emitting module that generates ultrabroadband near-infrared light and increasing the output power. The light emitting module includes a linearly polarized laser pump for generating a visible laser, a half-wave plate for adjusting the polarization orientation of the visible laser, and a crystal optical fiber disposed on the output light path of the half-wave plate. The core of the crystal optical fiber is made of forsterite (Mg.sub.2SiO.sub.4) doped with Cr.sup.3+ and Cr.sup.4+ ions. The doping process includes: depositing a chromium oxide layer on the lateral surface of the core and driving the chromium atoms into the core by high temperature diffusion; coupling the visible laser into the core to produce a spontaneous emission with wavelengths from 750 to 1350 nm continuously. Particularly, the continuous spectrum is adjustable by changing the polarization orientation of the visible laser via the half-wave plate.

An apparatus is described. The apparatus comprises a downstream wavelength selective switch having an input port, an optical path operable to carry an optical signal, an optical source providing amplified spontaneous emission (ASE) light, an optical switch having a first input coupled to the optical path, a second input coupled to the optical source and receiving the ASE light, and an output coupled to the input port of the downstream wavelength selective switch. The optical switch couples either the first input or the second input to the output. Further included is a photodiode operable to monitor the optical signal, detect an optical loss of signal of the optical signal, and output a switch signal to the optical switch such that the optical switch couples the second input receiving the ASE light to the output whereby the ASE light is directed to the input port of the downstream wavelength selective switch.

An apparatus includes an amplified spontaneous emission source, which in turn includes an optical fiber. The optical fiber includes a solid core and a first end. The solid core includes a silica matrix. The silica matrix includes a rare-earth element and a glass co-dopant. The rare-earth element includes dysprosium or neodymium. The glass co-dopant includes Al.sub.2O.sub.3. The apparatus further includes a laser pump diode coupled to the first end of the optical fiber. The laser pump diode and the optical fiber cooperate to generate a spontaneous spectral emission confined to the solid core. The spontaneous spectral emission includes a simultaneous plurality of spectral regions.

The present invention discloses a narrow-band, low-noise Raman fiber laser with a random fiber laser pump, pertaining to the technical field of fiber lasers and comprising an ytterbium-doped random fiber laser for producing ytterbium-doped random fiber lasing as the pump of a cascaded Raman random laser; the ytterbium-doped random fiber laser consists of a pump light source, a pump combiner, an ytterbium-doped fiber and a single-mode fiber connected in sequence, as well as a first narrow-band reflector connected to the signal end of the pump combiner. Ytterbium-doped random fiber lasing as the pump of the pump light source disclosed in the present invention is produced by an ytterbium-doped random fiber laser consisting of a narrow-band point reflector, an ytterbium-doped fiber, and a single-mode fiber and further serves as the pump of a Raman light source to achieve random laser output. The Raman fiber laser with a random fiber laser pump provided by the present invention is significantly better in time-domain stability and relative intensity noise than conventional Raman fiber lasers owing to the application of ytterbium-doped random fiber lasing with modeless spectrum as the pump.

An apparatus includes an amplified spontaneous emission source, which in turn includes an optical fiber. The optical fiber includes a solid core and a first end. The solid core includes a silica matrix. The silica matrix includes a rare-earth element and a glass co-dopant. The rare-earth element includes dysprosium or neodymium. The glass co-dopant includes Al.sub.2O.sub.3. The apparatus further includes a laser pump diode coupled to the first end of the optical fiber. The laser pump diode and the optical fiber cooperate to generate a spontaneous spectral emission confined to the solid core. The spontaneous spectral emission includes a simultaneous plurality of spectral regions.

An amplified spontaneous emission (ASE) light source and a method for using the ASE light source are provided. The ASE light source may include a seed stage light source for providing a light beam to be amplified. The apparatus may include a tunable element coupled to the seed stage light source configured for filtering a portion of the light beam from the seed stage light source. The apparatus may include a loopback circuit coupled to the tunable element, the loopback circuit comprising a booster stage element for amplifying light from the tunable element.

The present invention provides an active fiber package for use in a fiber laser, amplifier, or ASE source comprising: a plate-shape base comprising a groove having a configuration of at least two spirals for receiving and fixedly holding an active fiber therein, said at least two spirals are coplanar enabling visibility of said active fiber, the outer loop of one spiral transitioning smoothly to the outer loop of another spiral, and the inner loop of each one of said spirals transitioning smoothly into a relatively short straight section; wherein a portion of said straight section of one of said spirals spliced to a coupling fiber, and wherein multiple inner loops of each one of said spirals in proximity to said straight section having a relatively low radius of curvature for enabling tight coiling of said active fiber, thus, for reducing thermal modal instability (TMI) and increasing lasing power.

The present invention provides an active fiber package for use in a fiber laser, amplifier, or ASE source comprising: a plate-shape base comprising a groove having a configuration of at least two spirals for receiving and fixedly holding an active fiber therein, said at least two spirals are coplanar enabling visibility of said active fiber, the outer loop of one spiral transitioning smoothly to the outer loop of another spiral, and the inner loop of each one of said spirals transitioning smoothly into a relatively short straight section; wherein a portion of said straight section of one of said spirals spliced to a coupling fiber, and wherein multiple inner loops of each one of said spirals in proximity to said straight section having a relatively low radius of curvature for enabling tight coiling of said active fiber, thus, for reducing thermal modal instability (TMI) and increasing lasing power.

A broadband optical amplifier for operation in the 2 μm visible wavelength band is based upon a single-clad Tm-doped fiber amplifier (TDFA). A compact pump source uses a combination of low-power laser diode with a fiber laser to provide a multi-watt pump beam without needing to include thermal management and/or pump wavelength stability components. The broadband optical amplifier is therefore able to be relatively compact device with fiber coupled output powers of >0.5 W CW, high small signal gain, low noise figure, and large OSNR, important for use as a versatile wideband preamplifier or power booster amplifier.