Abstract: A fiber optic device comprises an optical lens element having a focal length greater than 2 mm, and an optical signal source or receiver mounted at the focal plane of the optical lens element and operative to communicate optical signals with a selectively transparent interference filter through the optical lens element. Methods for the production and use of the fiber optic devices are also disclosed.

Abstract: Improved optical element wafers comprising stacked, optically coupled etalon wafers are disclosed. Each etalon wafer comprises a bulk optic wafer defining the optic cavity between selectively transparent thin film mirror coatings. The bulk optic wafer comprises an optically transparent body, such as a portion of a substrate wafer, along with a wedge correcting coating on at least one of the two surfaces of the optically transparent body and/or a thickness-adjustment layer on one or both surfaces. The bulk optic wafer is a solid, self-supporting body, optically transparent (at the wavelength or wavelengths of interest), whose thickness, i.e., the dimension between the selectively transparent surfaces, defines the cavity spacing of the bulk optic etalon wafer. Methods of making and using the optical element wafers are also disclosed.

Abstract: Optical filter elements and optical systems comprise optically mismatched etalons and optically mismatched stacked, optically coupled etalons that are directly optically coupled, at least one of the etalons or stacked, optically coupled etalons comprising first and second selectively transparent thin film mirror coatings on opposite surfaces of a bulk optic. The optically mismatched etalons can be configured to selectively pass single passbands. The disclosed optical systems optionally comprise other devices optically coupled to the optically mismatched etalons and optionally mismatched stacked, optically coupled etalons.

Abstract: A fiber optic device comprises an optical lens element having a focal length greater than 2 mm, and an optical signal source or receiver mounted at the focal plane of the optical lens element and operative to communicate optical signals with a selectively transparent interference filter through the optical lens element. Methods for the production and use of the fiber optic devices are also disclosed.

Abstract: Optical elements comprise stacked, optically matched and optically coupled etalons, at least one of the optically coupled etalons comprising first and second selectively transparent thin film mirror coatings on opposite surfaces of a bulk optic. The bulk optic defines the cavity spacing of the etalon and may, for example be formed of a monolithic body of silica or other optically transparent glass diced from a glass wafer. The bulk optic may further comprise a wedge coating of progressively increasing thickness overlying the monolithic glass body and compensating for, or offsetting non-parallelism of the bulk optic. The bulk optic may further comprise a thickness-adjustment layer of substantially uniform thickness. The disclosed optical elements optionally comprise other devices optically coupled to the stacked etalons. Novel methods are disclosed for producing the stacked etalons.

Abstract: An optical system and method are disclosed for multiplexing or de-multiplexing channels within a wavelength band. The optical signals carried on the system comprise separate channels 1 through n, each having a unique passband and a center wavelength spaced from the center wavelength of adjacent channels by d nm. The signals are semi-multiplexed, demultiplexed, or semi-demultiplexed by an interleaver comprising optically matched and directly optically coupled etalons. Periodic spectral passbands of width less than d nm, spaced from each other a distance of zd, where z is an integer greater than or equal to 3, are substantially transmitted through the interleaver. At least one of the etalons is a bulk optic etalon and comprises first and second selectively transparent thin film mirror coatings on opposite surfaces of a bulk optic that defines the cavity spacing of that etalon.

Abstract: An optical monochromator has high signal selectivity and low insertion loss, and is well-suited for characterizing a variety of optical signals, including closely-spaced optical channels within DWDM systems. The optical monochromator includes a bulk-optic polarization beam splitter that separates orthogonal polarization states of an applied optical signal into separate optical beams. Low insertion loss is achieved by reconciling the polarization states of the separate optical beams to an optimum polarization state that minimizes insertion loss when the optical beams are applied to a dispersive element. High signal selectivity is achieved using a multipass configuration and by illuminating large areas of the dispersive element, since large beam diameters are accommodated by the bulk-optic polarization beam splitter.

Abstract: A fiber optic sensor comprises a length of optical fiber, forming a loop, and a fiber optic directional coupler for optically closing the loop. The loop and coupler form a resonant cavity for light circulating therethrough. A PZT cylinder, about which the fiber loop is wrapped, is utilized to control the total round trip phase delay of the circulating light, and thus, control the intensity of the optical output signal. The phase delay is adjusted to a point where the optical output signal is at maximum sensitivity to changes in phase. When the fiber loop is exposed to, e.g., acoustic waves, the loop length changes correspondingly, thereby causing the phase delay, and thus, the optical output signal to vary. By detecting variations in output signal intensity, the frequency and intensity of the acoustic waves may be determined. The sensor also includes a feedback system for stabilizing the fiber loop against low frequency thermal drift.

Abstract: A Brillouin ring laser comprises a fiber optic resonator formed from a loop of fiber optic material and a fiber optic directional coupler for optically closing the loop.

Abstract: A fiber optic resonator comprises a single strand of optical fiber forming a loop and a fiber optic directional coupler for optically closing the loop. The length of the loop is selected to cooperate with the phase shift of the coupler to provide a resonant cavity, and the coupling constant is selected to provide full or maximum resonance with zero output power.