Optical waveguide amplifier and laser
AssigneePolaroid Corporation
InventorHong Po
Life of this patent
Estimating the term…
Abstract
A resonant waveguide cavity, preferably a loop, is fabricated from an active material doped host glass and includes a wavelength dispersive lateral coupling designed to preferentially support wavelengths in a selected bandwidth. Pumping light is provided to excite the active material so that the supported wavelengths stimulate in phase emission to increase their amplitude with the amplified signal presented to an output fiber. Where a signal generator is desired, the pumping light can be used to drive the resonant cavity into oscillation to provide a CW output at one of the cavity supported wavelengths.
Claims29
An optical waveguide device for tapping a trunk line carrying a set of optical signals to amplify one or more select signals form the set and transfer the amplified signals to another line for further travel therealong, said waveguide device comprising:
- (a) a first optical waveguide cavity for coupling to the trunk line and extracting from it at least a portion of the energy of a group of optical signals at wavelengths that encompass said select signals, said first optical waveguide cavity being resonant for said group of signals,
- (b) a resonant gain optical waveguide cavity coupled to said first resonant optical waveguide cavity to receive said portion of said group of signals resonant therein, said resonant gain optical waveguide being coresonant with said first resonant optical waveguide cavity at wavelengths corresponding to those of said select signals and comprising an active gain material with given absorption and fluorescence spectrums wherein said flurorescence spectrum has an emission band that encompasses said select optical signals and wherein said resonant gain optical waveguide cavity further includes means for precluding amplification of optical signals at wavelengths other than those corresponding to said select optical signals;
- and
- (c) means for introducing pumping energy within said absorption band into said resonant gain optical waveguide cavity in an amount below the lasing threshold thereof to amplify only said select signals.
A laser comprising:
- a gain cavity including a single mode optical waveguide having a core and a cladding, said core including an active gain material with given absorption and fluorescence spectrums wherein said fluorescence spectrum has an emission band that encompasses a predetermined spectral region, said waveguide being laterally coupled to itself at a given point to form a loop with one end thereof extending therefrom, said point of coupling defining an optical resonant cavity length within a given resonant band encompassed by said broad spectral region;
- pumping means for introducing pump light into said core within said given absorption spectrum at said extended end of said waveguide in an amount sufficient to cause lasing action within at least said given resonant band;
- and
- means for extracting light energy within said given resonant band from said loop.
A laser comprising:
- a pair of optical waveguide cavities where one of said waveguide cavities is a gain cavity in the form of a single mode waveguide having a core and a cladding where at least one of said core and cladding includes an active gain material with given absorption and fluorescence spectrums wherein said fluorescence spectrum as an emission band that encompasses a predetermined spectral region, said waveguide cavities being coupled with one another and structured to be coresonant at a select wavelength within said broad spectral region but otherwise not;
- means for introducing pump light into said gain cavity within said absorption spectrum to simulate lasing action to provide oscillation within said gain cavity at said select wavelength;
- and
- means for extracting light energy at only said select wavelength so that the output of said laser is at only said select wavelength.
An integrated optics waveguide device for amplifying light energy responsive to optical pumping, said device comprising:
- a substrate transmissive at the wavelength of the pump light;
- a resonant optical waveguide cavity formed in said substrate with a core of higher index than the material surrounding it, said core including an active gain material with given absorption and fluorescence spectrums wherein said fluorescence spectrum has an predetermined spectral region, said waveguide cavity being structured to be resonant at at least one wavelength encompassed by a given emission band within said broad spectral region;
- input coupling means for introducing said one select wavelength to said cavity;
- and
- output coupling means for extracting amplified light energy of said one wavelength from said cavity.
An optical waveguide device for tapping from a waveguide trunk line carrying a set of optical signals only a portion of one or more select signals and then amplifying those select signals so that the remainder of them are available for subsequent downline use, said waveguide device comprising:
- at least one waveguide resonator that is resonant at wavelengths corresponding to those of the select signals, said wavelength resonator having a portion for evanescently coupling to a complementary portion of the waveguide trunk line for transferring from the waveguide trunk line to said waveguide resonator at least a portion of the energy of a group of optical signals that encompass said select signals, said waveguide resonator further including active gain material along the optical path traveled by said select signals, said gain material having given absorption and fluorescence spectrum where said fluorescence spectrum has an emission band that encompasses said select optical signals to be amplified, said waveguide resonator further including wavelength selective means for precluding amplification of signals other than said select signals and another portion for evanescently coupling with a complementary portion of a branch line for transferring amplified signals to the branch line for further travel therealong;
- and
- means for introducing pumping energy within said absorption band of said gain material into said waveguide resonator in an amount below the lasing threshold for said waveguide resonator to provide only enough gain thereon to amplify only said select signals when present in said waveguide resonator.
Dependencies are inferred from the claim text.