Example optical amplification apparatus and example signal amplification methods are provided. One example optical amplification apparatus is connected to an optical fiber. The optical amplification apparatus includes a first pump laser and a first gain medium. The first pump laser is configured to emit first pump light. The first gain medium is configured to receive the first pump light and first multi-channel optical signals from the optical fiber; and perform gain amplification on the first multi-channel optical signals based on the first pump light, where the first pump light overlaps each of the first multi-channel optical signals in the first gain medium.

Some embodiments may include a packaged laser diode assembly, comprising: a length of optical fiber having a core and a polymer buffer in direct contact with the core, the length of optical fiber having a first section and a second section, the first section of the length of optical fiber including a tip of an input end of the optical fiber, wherein the polymer buffer covers only the second section of the first and second sections; one or more laser diodes to generate laser light; means for directing a beam derived from the laser light into the input end of the length of optical fiber; a light stripper attached to the core in the first section of the length of optical fiber. Other embodiments may be disclosed and/or claimed.

A Raman amplifier includes a first light source that outputs a primary pumping light, which propagates in a same direction as a propagation direction of a signal light, to an optical transmission line for Raman amplification, a second light source that outputs a secondary pumping light, which pumps and amplifies the primary pumping light and propagates in the same direction as the propagation direction, to the optical transmission line, and a control unit that controls a gain for the signal light by adjusting power of the secondary pumping light.

A dual output laser diode may include first and second end facets and an active section. The first and second end facets have low reflectivity. The active section is positioned between the first end facet and the second end facet. The active section is configured to generate light that propagates toward each of the first and second end facets. The first end facet is configured to transmit a majority of the light that reaches the first end facet through the first end facet. The second end facet is configured to transmit a majority of the light that reaches the second end facet through the second end facet.

A light source for Raman amplification to Raman-amplify signal light includes: plural incoherent light sources that output incoherent light; plural pumping light sources that output second-order pumping light; an optical fiber for Raman amplification to Raman-amplify the incoherent light with the second-order pumping light, and outputs the amplified incoherent light; and an output unit connected to the optical transmission fiber, receiving the amplified incoherent light, and outputting the amplified incoherent light as first-order pumping light having a wavelength that Raman-amplifies the signal light to the optical transmission fiber.

Gain switched laser diode pulses are used as seed pulses for optical pulse generation. ASE is reduced by applying a prebias to the laser diodes at an amplitude less than that associated with a laser diode threshold. An electrical seed pulse having an amplitude larger than that associated with laser threshold is applied within about 10-100 ns of the prebias pulse. The resulting laser diode pulse can be amplified in a pumped, rare earth doped optical fiber, with reduced ASE.

A pulsed fiber generator is configured with a unidirectional ring waveguide configured to emit a train of pulses. The ring waveguide includes multiple fiber amplifiers, chirping fiber components coupled to respective outputs of first and second fiber amplifiers, and multiple spectral filters coupled to respective outputs of the chirping components. The filters have respective spectral band passes centered around different central wavelengths so as to provide leakage of light along the ring cavity in response to nonlinear processes induced in the ring cavity. The pulse generator operates at a preliminary stage during which it is configured to develop a pitch to a signal, and at a steady stage during which it is configured to output a train of pulses through an output coupler at most once per a single round trip of the signal.

A method for providing spectral beam combining (SBC) including generating a plurality seed beams each having a central wavelength and a low fill factor profile, where the wavelength of all of the seed beams is different; amplifying the seed beams; causing the amplified beams to expand as they propagate so as to be converted from the low fill factor profile to a high fill factor profile where the high fill factor profile tapers to a lower value at a perimeter of each beam; causing a wavefront of the converted beams to flatten to provide a plurality of adjacent SBC beams having different wavelengths with minimal overlap and a minimal gap between the beams; collimating the SBC beams; and directing the collimated SBC beams onto an SBC element that spatially diffracts the individual beam wavelengths and directing the beams in the same direction as a combined output beam.

A device for cooling a laser diode pump comprising a Low Size Weight Power Efficient (SWAP) Laser Diode (LSLD) assembly, including a laser diode coupled to a submount on a first surface, the submount comprising a first thermally conductive material and a heatsink coupled to a second surface of the submount, wherein the heatsink comprises a second thermally conductive material, the heatsink comprising one or more members formed on a side opposite the coupled submount. The device further comprising a housing coupled to the LSLD assembly, the housing comprising a carrier structure having an aperture configured to support the LSLD assembly on a first side and having a plurality of channels on a second side, a bottom segment configured to couple to the carrier segment to create an enclosure around the channels between a top side of the bottom segment and the second side of the carrier structure, an inlet and outlet formed in the housing for transporting a coolant into and out of the channels in the enclosure, wherein the members are disposed within the enclosure so as to expose the members to the coolant.

An optical crystal can be mounted to a mounting block configured to receive the crystal. A base portion on the mounting block utilizes two walls forming a corner and a single biasing spring clip to secure the crystal. The spring clip applies forces in two different directions substantially orthogonal to the two walls. The spring clip is based off a symmetrical geometry which applies nearly the same force application in both directions. The spring also features bend regions that contact the crystal in such a way as to reduce the presence of point loads or stress risers. The length of contact along the crystal is maximized, allowing for proper force distribution and a sufficient surface are contact for static holding capabilities.