Abstract: An optical isolator unit is aligned, assembled, and subsequently diced into smaller isolator chips for placement in a micro-optical bench, along with input and an output fiber coupling ball lenses. Polarizers (for polarization-dependent isolators) or birefringence walkoff crystals (for polarization-independent isolators) are aligned and then glued together with 45.degree. Faraday rotators using an optical-grade adhesive. The surfaces of the components are AR-coated to match the index of the optical-grade adhesive. An optical isolator unit formed in this manner is then diced into a plurality of optical isolator chips with a high-speed wafer saw. The optical isolator unit is preferably mounted on any one of its sides in such a way that only a smallest possible cutting depth is required for dicing, i.e., it is mounted such that a thinnest dimension of the isolator is presented for cutting, such that material loss due to cutting is reduced and delamination of the optical isolator chips is prevented.

Abstract: The optical component comprises a first I/O port, a second I/O port and a polarization-changing optical element located between the first I/O port and the second I/O port. The second I/O port is optically aligned with the first I/O port. The first I/O port includes a first opposed walk-off crystal pair and a second opposed walk-off crystal pair. The second opposed walk-off crystal pair is a mirror image of the first opposed walk-off crystal pair. Each opposed walk-off crystal pair comprises two walk-off crystals. Each walk-off crystal has a walk-off direction. Each walk-off crystal includes an attachment face substantially parallel to the walk-off direction, a first face orthogonal to the attachment faces, and a second face opposite the first face. The walk-off crystals are attached to one another with their attachment faces in contact, and their walk-off directions opposed.

Abstract: A tunable laser that includes a laser amplifier and an acousto-optic filter (AOTF). The AOTF includes a waveguide having first and second ports. A first polarization filter passes light of a first polarization state, the first polarization filter being located between the laser amplifier and the first port of the AOTF. The laser also includes a first asymmetrical polarization rotator located between the first port of the AOTF and the first polarization filter. The first asymmetrical polarization rotator rotates the polarization of light traveling from the first port of the AOTF to the first polarization filter by 90.degree. while leaving unchanged the polarization of light traveling from the first polarization filter to the first port of the AOTF. A mirror reflects light leaving the second port of the AOTF back into the second port of the AOTF.

Abstract: A switching element defines a transmitting state and a reflecting state for a pair of intersecting waveguides that have a gap at their intersection. In the preferred embodiment, the switching element exhibits total internal reflection at the gap sidewall from one waveguide to the other when not in the transmitting state. In the transmitting state, index-matching liquid fills the gap, enabling light to continue in the original waveguide direction. The switching element may use ink jet techniques or bubble techniques to displace index-matching liquid. The index-matching fluid may be projected from a gap between the waveguides by a jet mechanism, or a vapor or dissolved gas bubble may be formed to fill the gap between the waveguides to provide the reflecting state for the switching element. Using either of the techniques, heaters are employed to initiate the switching operation. In some embodiments, more than one heater is utilized.

Abstract: A polarization independent acousto-optical tunable filter (AOTF). The AOTF is fabricate with two waveguides formed on a single substrate. An incoming polarization independent beam of light is split into TE and TM optical components with a walk-off crystal wherein each optical component is coupled into a different one of the two waveguides. The AOTF can be formed to provide two stages of filtering. The two stages of filtering can be realized be providing two successive stages or by passing the optical signal through the same filter twice. Various configurations are obtained by placing TM and TE polarizers within the optical path traveled by the incoming beam of light.

Abstract: An apparatus for aligning a plurality of optical fibers in predetermined positions with respect to one another. The apparatus includes a top plate and a bottom plate having a first set of alignment groves therein, there being one such grove corresponding to each optical fiber. The alignment groves are positioned such that the optical fibers will be in their correct positions with respect to one another when the optical fibers are forced against the bottom of the groves by the top plate. To reduce reflections from cut fiber ends that would normally be cut and polished, the optical fibers are cut at an angle with respect to the axis of the optical fiber and the cut end is bonded to an optical flat by a glue layer having the same index of refraction as the optical fiber. In the preferred embodiment of the present invention, the optical flat also includes an anti-reflective material on the non-glued surface thereof.

Abstract: A CPM mode-locked fiber ring laser including an ion-implanted semiconductor saturable absorber providing sub-picosecond pulses at rapid repetition rates. The laser provides compact, turn-key capability and is polarization insensitive.

Abstract: A resonator in which the input and output transducers are positioned to couple strongly into a resonant mode of interest. Signal drains are included to drain energy out of spurious resonant modes. In a magnetostatic wave resonator, the signal drains are preferably grooves in the surface of the ferrimagnetic film forming the resonator cavity.

Abstract: A magnetostatic wave resonator having a transducer oriented such that it is tangent at all points to a wavefront of a traveling wave component of a resonant mode of the resonant cavity. In a rectangular cavity of width L.sub.x and length L.sub.y, the transducer is perpendicular to the wavevector k=(m.pi./L.sub.x)e.sub.x +(n.pi./L.sub.y)e.sub.y for some nonzero integers m and n, whereby the transducer optimally transfers energy into the resonant mode that is a linear superposition of travelling waves that includes this wavevector. This enhances coupling into the resonant mode of interest and reduces the amount of coupling into spurious modes.