摘要:
A stabilized laser source includes a fiber-ring Brillouin laser that incorporates a circulator for non-reciprocal operation and for launching of a pump optical signal. Most of the pump optical signal is launched in a forward direction and drives Brillouin laser oscillation in the backward direction, a portion of which exits via an optical coupler as the optical output of the laser source. A small fraction of the pump optical signal is launched in the backward direction via the optical coupler, and a fraction of that backward-propagating pump optical signal exits via the optical coupler as an optical feedback signal. A frequency-locking mechanism receives the optical feedback signal and controls the pump optical frequency to maintain resonant propagation of the backward-propagating pump optical signal. A second pump optical signal can be launched in the forward direction to generate a second Brillouin laser oscillation.
摘要:
A disk resonator is pumped by counterpropagating pump signals to produce corresponding counterpropagating Brillouin laser signals. The pump laser optical frequencies are separated by a frequency offset ΔνP but excite the same nominal resonator optical mode; the Brillouin laser optical frequencies are separated by a beat frequency ΔνL with 0
摘要:
A disk resonator is pumped by counterpropagating pump signals to produce corresponding counterpropagating Brillouin laser signals. The pump laser optical frequencies are separated by a frequency offset ΔνP but excite the same nominal resonator optical mode; the Brillouin laser optical frequencies are separated by a beat frequency ΔνL with 0
摘要:
A ring optical resonator is formed on a substrate. An outer circumferential surface of the resonator substantially confines one or more circumferential resonant optical modes. The resonator is positioned above a void formed in the substrate and is supported above the void by a portion of a material layer on the substrate that extends radially inward above the void from an outer circumferential edge of the void to the outer circumferential surface of the resonator. An optical waveguide can be integrally formed on the substrate and traverses a portion of the material layer above the void. The optical waveguide and the ring optical resonator are arranged and positioned so as to establish evanescent optical coupling between them. Q-factors of 108 or more have been achieved with a silica resonator and silicon nitride waveguide integrally formed on a silicon substrate.
摘要:
A ring optical resonator is formed on a substrate. An outer circumferential surface of the resonator substantially confines one or more circumferential resonant optical modes. The resonator is positioned above a void formed in the substrate and is supported above the void by a portion of a material layer on the substrate that extends radially inward above the void from an outer circumferential edge of the void to the outer circumferential surface of the resonator. An optical waveguide can be integrally formed on the substrate and traverses a portion of the material layer above the void. The optical waveguide and the ring optical resonator are arranged and positioned so as to establish evanescent optical coupling between them. Q-factors of 108 or more have been achieved with a silica resonator and silicon nitride waveguide integrally formed on a silicon substrate.
摘要:
A microwave-frequency source, generating an output electrical signal at an output frequency fM, comprises a pump laser source, an optical resonator, and a photodetector. Free spectral range vFSR of the optical resonator equals an integer submultiple of a Brillouin shift frequency vB of the optical resonator (i.e., vB=MvFSR). The pump laser source is frequency-locked to a corresponding resonant optical mode of the optical resonator. Pumping the optical resonator with output of the pump laser source at a pump frequency vpump results in stimulated Brillouin laser oscillation in the optical resonator at respective first, second, and third Stokes Brillouin-shifted frequencies v1=vpump−vB, v2=vpump−2vB, and v3=vpump−3vB. The photodetector receives stimulated Brillouin laser outputs at the first and third Stokes Brillouin-shifted frequencies v1 and v3 and generates therefrom the output electrical signal at a beat frequency fM=v1−v3=2vB. The output electrical signal at the output frequency fM exhibits exceptionally low phase noise.
摘要:
A frequency comb generator fabricated on a chip with elimination of a disadvantageous reflow process, includes an ultra-high Q disk resonator having a waveguide that is a part of a wedge structure fabricated from a silicon dioxide layer of the chip. The disk resonator allows generation of a frequency comb with a mode spacing as low as 2.6 GHz and up to 220 GHz. A surface-loss-limited behavior of the disk resonator decouples a strong dependence of pumping threshold on repetition rate.
摘要:
A dual-comb optical-frequency comb generator includes a tunable comb-generating laser, a coarse-comb generator, a fine-comb generator, a second harmonic generator, a coarse-comb offset photodetector, a dual-comb offset photodetector, and a fine-comb photodetector. The coarse comb is self-referencing and coupled to the fine comb so as to enable absolute determination of the frequencies of the fine comb.
摘要:
An optical apparatus comprises a waveguide substrate and an optical reference cavity. The optical reference cavity comprises an optical waveguide formed on the waveguide substrate and arranged to form a closed loop greater than or about equal to 10 cm in length. The RMS resonance frequency fluctuation is less than or about equal to 100 Hz. The Q-factor can be greater than or about equal to 108. The optical waveguide can exhibit optical loss less than or about equal to 0.2 dB/m for propagation of an optical signal along the optical waveguide. The closed loop path can comprise two or more linked spirals greater than or about equal to 1 meter in length and can occupy an area on the waveguide substrate less than or about equal to 5 cm2.
摘要:
A microwave-frequency source, generating an output electrical signal at an output frequency fM, comprises a pump laser source, an optical resonator, and a photodetector. Free spectral range vFSR of the optical resonator equals an integer submultiple of a Brillouin shift frequency vB of the optical resonator (i.e., vB=MvFSR). The pump laser source is frequency-locked to a corresponding resonant optical mode of the optical resonator. Pumping the optical resonator with output of the pump laser source at a pump frequency vpump results in stimulated Brillouin laser oscillation in the optical resonator at respective first, second, and third Stokes Brillouin-shifted frequencies v1=vpump−vB, v2=vpump−2vB, and v3=vpump−3vB. The photodetector receives stimulated Brillouin laser outputs at the first and third Stokes Brillouin-shifted frequencies v1 and v3 and generates therefrom the output electrical signal at a beat frequency fM=v1−v3=2vB. The output electrical signal at the output frequency fM exhibits exceptionally low phase noise.