Abstract: An optical transmitter includes a light source and an SBS suppression circuit coupled to the light source. The light source is operable to generate an optical signal having one or more wavelengths. The optical signal has a signal spectrum having an upper band limit and a lower band limit. The SBS suppression circuit is operable to communicate a noise current for receipt by the light source. The noise current is operable to broaden the signal spectrum of the optical signal. The light source operates to convert the noise current into a noise component of the signal spectrum that resides between the upper band limit and the lower band limit.

Abstract: In one embodiment, an optical amplifier includes a gain medium operable to receive a plurality of signals each having a center wavelength and a noise figure associated with at least a portion of the amplifier and varying as a function of wavelength. At least two of the plurality of signals have launch powers that are a function of a magnitude of the noise figure measured at or near the center wavelength of that signal.

Abstract: In one aspect of the invention, a system operable to reduce degradation of an optical signal to noise ratio where signals having multiple wavelengths are communicated over a common optical link includes an amplifier assembly operable to introduce to a lower communication band a first gain and to introduce to a higher communication band a second gain that is different from the first gain. In addition, the system is operable to introduce a variable gain tilt into at least one of the communication bands. The different gains introduced to the higher and lower bands and the variable gain tilt introduced into at least one of the bands result in a reduction of a degradation of optical signal to noise ratio that could otherwise be caused by wavelength dependent attenuation when the communication bands are combined and communicated over an optical link.

Abstract: A Raman fiber amplifier includes: a transmission fiber; at least one optical pump providing optical pump power to the transmission fiber; and at least one pump power detector; at least one signal detector detecting signal power propagating through the transmission fiber. The Raman fiber amplifier also includes a controller that adjusts the pump power provided by the pump to adjust, gain, or signal power provided by this Raman fiber amplifier.

Abstract: In one aspect of the invention, a control system for use in an optical amplifier includes a plurality of control legs, each operable to receive one of plurality of portions of an optical signal, wherein each of the plurality of portions comprises a different percentage of the optical signal. The system further includes a plurality of registers, each associated with one of the control legs and each operable to store a value proportional to the portion of the optical signal communicated in the associated control leg. The system also includes a controller operable to select one of the values stored in one of the plurality of registers and to scale that value by a scaling factor to generate a scaled value, wherein the scaling factor is determined at least in part by the percentage of the optical signal associated with that value. The controller is operable to generate, based at least in part on the scaled value, a control signal operable to affect the gain of the amplifier.

Abstract: In one aspect of the invention, a system operable to reduce degradation of an optical signal to noise ratio where signals having multiple wavelengths are communicated over a common optical link includes an amplifier assembly operable to introduce to a lower communication band a first gain and to introduce to a higher communication band a second gain that is different from the first gain. In addition, the system is operable to introduce a variable gain tilt into at least one of the communication bands. The different gains introduced to the higher and lower bands and the variable gain tilt introduced into at least one of the bands result in a reduction of a degradation of optical signal to noise ratio that could otherwise be caused by wavelength dependent attenuation when the communication bands are combined and communicated over an optical link.

Abstract: An optical waveguide laser, preferably a fiber laser, has unintentionally incorporated impurities disposed in the lasing medium which upconvert a portion of the lasing radiation to radiation of shorter wavelength, thereby introducing defects in the medium which result in increased absorption due to photodarkening. Suitable rare-earth co-dopants are intentionally incorporated during the manufacture of the fiber for effectively shunting the upconversion process. The lifetime of the fiber laser is thereby increased.

Abstract: An all-optical modulator for modulating the output power of a high-power optical pump source is disclosed. More particularly, with the optical modulator of the invention, the output power of a CW fiber laser is modulated by a low-power laser, such as a diode laser. The modulator comprises two optical couplers which are preferably wavelength-selective and interconnected by a nonlinear single mode optical fiber with a high Raman gain. A laser system comprising a high-power pump laser, a fast signal laser with a suitable modulation depth and the optical modulator of the invention can advantageously employed in materials processing and graphics arts printing applications.

Abstract: A diode-pumped monolithic laser is fabricated from a self-doubling host material co-doped with two ionic species, where one ionic dopant converts pump radiation to continuous radiation at a fundamental frequency and the other dopant acts as a saturable absorber to Q-switch the fundamental radiation which is then frequency doubled to produce pulsed high-intensity green light, the green light being either outputted or further frequency-doubled, into pulsed coherent UV radiation, by means of a non-linear crystal.

Abstract: Novel solid state gain mediums provide monolithic lasers with short cavity lengths and with the ability to efficiently lase in the lowest order TEM.sub.00 mode. Unoptimized optical power conversion efficiency of 35% has been achieved with the novel solid state gain mediums in monolithic lasers that have a cavity length as short as 0.5 mm. With proper values for the output mirror reflectivity and low loss host crystals, the optical power conversion efficiency is approximately 50%. Moreover, when in optical contact with a frequency doubling optically non linear crystal, the novel solid state gain mediums in the monolithic lasers can produce coherent visible light.

Abstract: A crystalline material for use in a solid state tunable laser is YAG:Mn wherein the Mn is predominantly trivalent. The laser is tunable in the yellow-orange range (0.59-0.63 .mu.m) and the near infrared range (1.04-1.2 .mu.m).

Abstract: An up converting method and apparatus includes a crystalline structure responsive to light emitted from pump light for producing visible and/or ultraviolet light therefrom which is of a shorter wavelength than the pump light. This crystalline structure comprises a composition containing active ions of trivalent rare earth elements and a host material of either anhydrous rare earth halides or rare earth oxysulfides. This crystalline structure is represented by the atomic formula M.sub.(1-x) R.sub.x Z.sub.3 or M.sub.2(1-x) R.sub.2x O.sub.2 S where M comprises at least one rare earth element selected from the group comprising cerium, gadolinium, yttrium, lanthanum, and mixtures thereof, R is a dopant selected from the group comprising neodymium, thulium, erbium, holmium, samarium, and mixtures thereof, x is a value in the range from 0.005 to 1.0, and Z is a halogen selected from the group comprising chlorine, bromine, and iodine.