Abstract: A photo-patternable perfluorinated silane sol-gel material is presented that exhibits a high refractive index and propagation losses below 1 dB/cm at the telecommunication wavelengths. The sol-gels are produced with general formula [(CH2)n,R?—Si(O)2]x—[Si(O)4]y—[R?—Si(O)3]z—[R?(CH2)n—M(O)3]w—[R??(CH2)n—Si(O)3]v where O is oxygen, Si is silicon, M is a metal alkoxyde known to form bonds with organic compounds through oxygen donor ligands, and where , R? and R?? are photo cross-linkable groups, and where (CH2)n are alkyl spacers with n being an integer ?0. The sol-gels can be fabricated to produce complex waveguide structures directly onto silica-on-silicon substrates with low bending losses.

Abstract: A low-cost approach is provided for forming a low splice loss, low back reflection loss and mechanically robust angle-fusion splice between a standard silica fiber and a low-temperature non-silica glass fiber. This is accomplished by angle cleaving the silica fiber, square cleaving the non-silica fiber and then asymmetrically heating the fibers to form an angle fusion splice. A matched angle at the end of the non-silica fiber is generated in situ during the splicing process. The tip of the angle-cleaved silica fiber may be polished flat back to the edge of the core to reduce the range of motion of the non-silica fiber during splicing thereby further reducing splice loss and enhancing the mechanical strength of the joint.

Abstract: A tellurite-based glass composition for use in EDFAs exhibits higher phonon energy without sacrificing optical, thermal or chemical durability properties. The introduction of boron oxide (B2O3) into the Er3+-doped tellurite glasses increases the phonon energy from typically 785 cm?1 up to 1335 cm?1. The inclusion of additional glass components such as Al2O3 has been shown to enhance the thermal stability and particularly the chemical durability of the boro-tellurite glasses. Er:Yb codoping of the glass does further enhance its gain characteristics.

Abstract: Phosphate glass fibers are an attractive alternative to silica fibers because they can be co-doped with much higher concentrations of Yb and Er and exhibit a higher optical gain per unit length. However, in such fibers the absorption of the pump is high and heating effects caused by the pump laser can cause a significant change in refractive index. This problem is overcome with a phosphate glass composition that exhibits a temperature coefficient of refractive index &bgr;=dn/dT close to zero. This is achieved by avoiding alkali metal oxides in the glass composition and by adjusting the concentration of the network modifiers such as BaO.

Abstract: A narrow-linewidth high-power single-frequency laser is realized by pumping a laser cavity with a pair of polarized single-mode pump lasers that are driven below their respective “micro-kink” regions and combined with a polarized beam combiner. The pump lasers emit at the same wavelength and include a length of polarization-maintaining (PM) fiber to maintain the polarization of the respective pumps. The laser cavity is selected from microchip, fiber and waveguide devices and is provided with optical feedback. This laser is capable of producing a stable high-power single-mode signal with a very narrow linewidth, e.g. less than 10 kHz and preferably less than 3 kHz.

Abstract: A method of finding drive values for an actuation mechanism having three degrees of freedom is provided, that will optimize a predetermined parameter of a system that utilizes the actuation mechanism. In one embodiment, a method of finding drive values for a tunable Fabry-Perot cavity is provided, for driving three independently adjustable actuators such that the cavity mirrors of the tunable Fabry-Perot cavity are maintained in a substantially parallel relationship.

Abstract: A compact low-cost continuous single-mode fiber laser delivers output powers in excess of 50 mW over the C-band (1530 nm-1565 nm). The phosphate glass fiber supports the high doping concentrations of erbium and ytterbium (Er:Yb) without self-pulsation that are required to provide sufficient gain per centimeter needed to achieve high power in the ultra short cavity lengths necessary to support single-mode lasers. The use of fiber drawing technology provides a lower cost solution than either combined solution doping/MCVD fiber fabrication or waveguide fabrication. The ability to multi-mode clad pump the fiber further reduces cost, which is critical to the successful deployment of fiber lasers in the burgeoning metro markets.

Abstract: A short laser cavity (up to 30 cm in length) comprising a free-space tunable MEMS Fabry-Perot filter, a collimating lens and a section of erbium-doped phosphate gain fiber (2-25 cm) is formed between a pair of broadband reflectors. The cavity is optically pumped to excite the erbium ions and provide gain, which establishes an initial longitudinal mode structure that spans the C-band with a mode spacing of at least 0.3 GHz and a roundtrip unsaturated gain of at least 8 dB over the tuning range. A controller tunes the MEMS filter, which has a filter function whose spectral width is at most ten and preferably less than four times the longitudinal mode spacing, to align its transmission maxima to one of a plurality of discrete output wavelengths that span the C-band. A thermal control element adjusts the longitudinal mode structure to align a single mode with the transmission maxima of the filter.

Abstract: A multi-port optical amplifier chip has an inner cladding layer sandwiched between a pair of outer cladding layers, a plurality of active core elements disposed substantially within the inner cladding layer to receive optical signals at respective input ports and transmit amplified optical signals at respective output ports, a pair of reflecting surfaces on opposing sides of the inner cladding and at least one pump source. The pump source directs pump light into the inner cladding layer where it is confined to bounce back-and-forth across the active core elements thereby enhancing the absorption of pump light into the core elements, hence increasing gain. Greater than 5 dB over the C-band (1930 nm-1965 nm) in less than 10 cm is expected with a phosphate glass material co-doped with greater than 2 weight percent Erbium and 10 weight percent Ytterbium. A number of fiber drawing based approaches are contemplated for manufacturing the amplifiers to achieve this performance and reduce cost.

Abstract: A compact, high-power, low-cost broadband ASE source is achieved by multi-mode pumping a highly doped multi-component glass fiber in standard ASE source configurations. The multi-mode pump is coupled into and propagates in the fiber cladding exciting the rare-earth dopant ions (Er,Yb) in the fiber core. The multi-component glass includes a network former selected from either phosphate (P2O5) or tellurite (TeO2) and is doped with at least 0.25 weight percent rare-earth dopants. The high concentrations of dopants supported by these glasses absorbs the multi-mode pump in a short length, less than 100 cm, and provides high saturated output powers.

Abstract: A detunable Fabry-Perot interferometer, and method of tuning a Fabry-Perot interferometer are provided. The Fabry-Perot interferometer includes a first mirror, a second mirror oriented with respect to the first mirror so as to define a Fabry-Perot cavity therebetween, and an actuator configured to adjust a resonant wavelength of the Fabry-Perot cavity by varying a gap between the first and second mirrors, wherein the actuator is configured to selectively maintain the first and second mirrors in a substantially non-parallel relationship while the resonant wavelength of the Fabry-Perot interferometer is varied. The detunable Fabry-Perot interferometer can be employed in a multiplexer of a telecommunications system, as provided.

Abstract: The present invention provides a compliant mechanism that can be used to make a variety of devices, such as tunable optical devices, that are more reliable, more cost effective, and/or exhibit better performance than prior art devices. In one embodiment, the complaint mechanism includes an island that is suspended from a frame using a compliant member that is attached to the frame and the island. Individual actuators and/or sensor elements may be placed on the island, so that each island may be individually actuated or sensed.

Abstract: A tellurite-based glass composition for use in EDFAs exhibits higher phonon energy without sacrificing optical, thermal or chemical durability properties. The introduction of boron oxide (B2O3) into the Er3+-doped tellurite glasses increases the phonon energy from typically 785 cm−1 up to 1335 cm−1. The inclusion of additional glass components such as Al2O3 has been shown to enhance the thermal stability and particularly the chemical durability of the boro-tellurite glasses. Er:Yb codoping of the glass does further enhance its gain characteristics.

Abstract: A compact, low-cost mid-gain Erbium Micro-Fiber Amplifier (EMFA) is provided by multi-mode pumping a micro fiber formed from a specialty multi-component glass and highly co-doped with Er:Yb. The specialty glass exhibits a much higher core absorption coefficient than standard glasses. As a result, the lower order modes are rapidly absorbed in the fiber core. The abrupt change in the mode profile perturbs the higher order modes and mode couples them into the lower order modes within a very short length of fiber, less than 20 cm. This “absorptive mode coupling” effect can double the absorption efficiency of a circular symmetric micro fiber and extend the length over which such a highly doped fiber can be efficiently inverted. The combination of multi-mode pumping with short fiber lengths reduces the form factor and cost of EMFAs.

Abstract: A method of finding drive values for an actuation mechanism having three degrees of freedom is provided, that will optimize a predetermined parameter of a system that utilizes the actuation mechanism. In one embodiment, a method of finding drive values for a tunable Fabry-Perot cavity is provided, for driving three independently adjustable actuators such that the cavity mirrors of the tunable Fabry-Perot cavity are maintained in a substantially parallel relationship.

Abstract: A low-cost approach provides a low loss and mechanically robust fusion splice between a standard silica fiber and a low-temperature multi-component glass fiber. An asymmetric heating configuration creates a temperature gradient between the silica and multi-component glass fibers that enhances diffusion, hence bond strength. The multi-component glass fiber may also be drawn with an outer cladding of a different multi-component glass. The outer cladding is selected so that it is thermally compatible with the multi-component glass used for the core and inner cladding and compatible with forming even stronger thermal diffusion bonds with the silica fiber.

Abstract: The meters of coiled silica fiber in conventional R-EDFAs is replaced with an ultra-short high-gain waveguides formed of co-doped erbium-ytterbium multi-component glass a few centimeters in length. The compact R-EDA is pumped using non-conventional multi-mode pumps that couple to the waveguide cladding. The multi-component glasses support doping concentrations of the rare-earth ions erbium and ytterbium far in excess of levels believed possible with conventional glasses. These dopant levels in combination with the reflective scheme make a compact R-EDA with sufficient amplification possible.

Abstract: A photo-patternable perfluorinated silane sol-gel material is presented that exhibits a high refractive index and propagation losses below 1 dB/cm at the telecommunication wavelengths. The sol-gels are produced with general formula [(CH2)n, R′—Si(O)2]x—[Si(O)4]y—[R′—Si(O)3]z—[R″(CH2)n-M(O)3]w—[R′″(CH2)n—Si(O)3]v where O is oxygen, Si is silicon, M is a metal alkoxyde known to form bonds with organic compounds through oxygen donor ligands, and where , R″ and R′″ are photo cross-linkable groups, and where (CH2)n are alkyl spacers with n being an integer ≧0. The sol-gels can be fabricated to produce complex waveguide structures directly onto silica-on-silicon substrates with low bending losses.

Abstract: The present invention provides method of making mechanisms in which the relative locations of elements are maintained during manufacturing. The methods according to the present invention can be used to make a variety of devices, including tunable optical devices. The methods include displaceably attaching an island (support) to a frame with a non-rigid material.

Abstract: A multimode diode package and pump-coupler package are provided with a beam rotator that facilitates efficient packaging of a multimode diode laser with a side-coupled optical fiber. The beam rotator comprises a pair of reflective surfaces that perform/a pair of “off-plane bounces” to rotate the beam's fast axis. In an XYZ coordinate system, if the diode lies in the XZ-plane and emits the beam along the Z-axis with its fast-axis along the Y-axis, the first reflective surface folds the beam along the Y-axis and its fast-axis along the Z-axis. The second reflective surface folds the beam along the X-axis and leaves the fast-axis along the Z-axis. The fiber is mounted in the XZ-plane along the Z-axis parallel to the fast-axis.