Abstract: A scaffold has a spiral configuration and gradient porosity designed to facilitate the healing of bone injuries. To make the scaffold, a sheet of polymeric material or the like is rolled into a spiral shape. In one embodiment, the resulting scaffold has an outer porous layer with high porosity, and a comparatively less porous inner layer in order to facilitate vascularization and promote recovery. The pores can be filled with a degradable polymer and/or growth factors, bioactive molecules, bactericidal drugs and/or other compositions to further promote recovery.

Abstract: The invention relates to optical devices comprising polarization diversity couplers. An embodiment of the invention relates to an optical device comprising a polarization diversity coupler configured to receive a beam of optical radiation. The optical device may further comprise a phase shifter, a 2×N coupler, a photodetector and a control unit configured to generate a control signal based on a monitor signal of the photodetector.

Abstract: A catheter and a console for a catheter. In one embodiment, the catheter includes: (1) a wall having a substantially annular cross-section and surrounding a bore, (2) a plurality of optical fibers associated with the wall and terminating at a distal end of the wall in end faces of differing, non-perpendicular orientation with respect to longitudinal axes of the plurality of optical fibers and (3) photoacoustic layers coupled to at least some of the end faces and configured to generate an ultrasonic signal in response to laser light transmitted along the plurality of optical fibers.

Abstract: Pressure sensors, a method of sensing pressure and a method of determining a change in birefringence of a polarization maintaining (PM) optical fiber. In one embodiment, the pressure sensor includes: (1) a source of laser light, (2) a polarization module coupled to the source and configured to modulate a polarization state of the light, (3) a PM optical fiber configured to receive the light into a proximal end thereof and having a sensor coupled to a distal tip of the PM optical fiber and having a pressure-dependent optical anisotropy and (4) a detector configured to receive the light back from the sensor via the proximal end and provide a signal based thereon that indicates a pressure on the sensor.

Abstract: Method and apparatus for noise reduction in ultrasound detection with the steps of: an optical interferometer having a reference arm and a signal arm that includes a polarization-maintaining probing fiber having a reflective coating at a distal end, a way to couple the probing fiber to ultrasound, a way to generate two output beams from the interferometer, a device to modulate the polarization state of the light in the probing fiber, and a detection mechanism responsive to the ultrasonic signals at the distal tip of the probing fiber.

Abstract: An imaging guidewire that, in one embodiment, includes: (1) a hypotube forming an elongated main body having a distal end, (2) at least one multimode optical fiber integral with the hypotube and configured to carry laser light for ultrasonic excitation, (3) a single-mode optical fiber integral with the hypotube, having a reflective coating located on a distal end thereof and at the distal end of the elongated main body and configured to carry laser light for ultrasonic detection and (4) an imaging cap coupled to the elongated main body at the distal end and including a photoacoustic layer configured to receive the laser light from the at least one multimode optical fiber.

Abstract: An ultrasonic pressure sensor and a method of detecting ultrasonic pressure. In one embodiment, the ultrasonic pressure sensor includes: (1) an interferometer having a reference arm and a signal arm that includes a probing fiber, the probing fiber having a reflective coating at a distal end thereof and configured to couple to ultrasonic waves proximate the distal end, the interferometer configured to receive laser light and produce two output beams based on the ultrasonic waves and (2) a photodetector coupled to the interferometer and configured to generate electronic signals based on the two output beams.

Abstract: Method and apparatus for noise reduction in ultrasound detection with the steps of: an optical interferometer having a reference arm and a signal arm that includes a polarization-maintaining probing fiber having a reflective coating at a distal end, a way to couple the probing fiber to ultrasound, a way to generate two output beams from the interferometer, a device to modulate the polarization state of the light in the probing fiber, and a detection mechanism responsive to the ultrasonic signals at the distal tip of the probing fiber.

Abstract: Various devices for ablating tissue in a lateral direction and methods of operation thereof. One embodiment of such a device includes: (1) an elongated body configured to carry ablative energy from an ablative energy source associated with a proximal end to a distal end and (2) a distal tip located at the distal end, the distal tip configured to deliver the ablative energy in a direction substantially lateral to a longitudinal axis of the elongated body.

Abstract: An ultrasonic pressure sensor and a method of detecting ultrasonic pressure. In one embodiment, the ultrasonic pressure sensor includes: (1) an interferometer having a reference arm and a signal arm that includes a probing fiber, the probing fiber having a reflective coating at a distal end thereof and configured to couple to ultrasonic waves proximate the distal end, the interferometer configured to receive laser light and produce two output beams based on the ultrasonic waves and (2) a photodetector coupled to the interferometer and configured to generate electronic signals based on the two output beams.

Abstract: Devices (i.e., catheters and guidewires) for, and methods of, ultrasonic imaging and ablation. In one embodiment, a device includes: (1) a fiber-optic bundle configured to carry laser light for ultrasonic imaging, each fiber of the fiber-optic bundle having a reflective layer oriented at an acute angle with respect thereto at a distal end thereof, (2) an elongated member associated with the fiber-optic bundle and configured to carry energy for ablation, the energy for ablation projecting past the distal end and (3) a photoacoustic layer associated with the each fiber of the fiber-optic bundle and configured to receive at least some of the laser light for the ultrasonic imaging and generate ultrasonic pressure waves in response thereto.

Abstract: A catheter and a console for a catheter. In one embodiment, the catheter includes: (1) a wall having a substantially annular cross-section and surrounding a bore, (2) a plurality of optical fibers associated with the wall and terminating at a distal end of the wall in end faces of differing, non-perpendicular orientation with respect to longitudinal axes of the plurality of optical fibers and (3) photoacoustic layers coupled to at least some of the end faces and configured to generate an ultrasonic signal in response to laser light transmitted along the plurality of optical fibers.

Abstract: An optical memory for storing and/or reading data on an optical disk. The optical disk incorporates a material in which holographic gratings can be created, and subsequently detected, at plural locations within the disk by an electro-optical head. Creation and detection of holographic gratings with variable diffraction efficiency is possible with the electro-optical head. Multiple holographic gratings can also be created at each one of the plural locations via a beam of light which has a different wavelength or point of focus. These data elements can be read by the electro-optical head using a beam of light sequentially varied in wavelength or point of focus to correspond to the multiple holographic gratings to be recorded.

Abstract: An optical wavelength router includes a beamsplitter, a first resonator, and a second resonator. The beamsplitter separates an input signal into a first beam and a second beam. The first resonator reflects the first beam and has a partially reflective front surface and a highly reflective back surface spaced a first optical thickness from the front surface. The second resonator reflects the second beam and has a partially reflective front surface and a highly reflective back surface spaced a second optical thickness from the front surface. The difference between the optical thicknesses of the first and second resonators is approximately equal to one-eighth wavelength.

Abstract: An optical wavelength router separates an input signal into two complementary output signals. A beamsplitter of the wavelength router separates the input signal into a first beam and a second beam. A first resonator reflects the first beam producing a group delay that is dependent on wavelength. Similarly, a second resonator reflects the second beam. The center wavelength of the second resonator is offset relative to that of the first resonator by one half of the free spectral range of the first resonator, so that the resonance frequencies of the second resonator are matched to the anti-resonance frequencies of the first resonator. The beams reflected by the resonators interfere within the beamsplitter to produce two output signals containing complementary subsets of the spectrum of the input signal (e.g., even optical channels are routed to a first output port and the odd optical channels are routed to a second output port).

Abstract: An optical wavelength router separates an input signal into two complementary output signals. A beamsplitter of the wavelength router separates the input signal into a first beam and a second beam. A first resonator reflects the first beam producing a group delay that is dependent on wavelength. Similarly, a second resonator reflects the second beam. The center wavelength of the second resonator is offset relative to that of the first resonator by one half of the free spectral range of the first resonator, so that the resonance frequencies of the second resonator are matched to the anti-resonance frequencies of the first resonator. The beams reflected by the resonators interfere within the beamsplitter to produce two output signals containing complementary subsets of the spectrum of the input signal (e.g., even optical channels are routed to a first output port and the odd optical channels are routed to a second output port).

Abstract: An optical wavelength router separates an input signal into two complementary output signals. A beamsplitter of the wavelength router separates the input signal into a first beam and a second beam. A first resonator reflects the first beam producing a group delay that is dependent on wavelength. Similarly, a second resonator reflects the second beam. The center wavelength of the second resonator is offset relative to that of the first resonator by one half of the free spectral range of the first resonator, so that the resonance frequencies of the second resonator are matched to the anti-resonance frequencies of the first resonator. The beams reflected by the resonators interfere within the beamsplitter to produce two output signals containing complementary subsets of the spectrum of the input signal (e.g., even optical channels are routed to a first output port and the odd optical channels are routed to a second output port).

Abstract: An apparatus for processing an optical signal includes a tunable optical element and a reflective element. The tunable optical element receives an input signal at an incidence angle and separates the input signal into a first beam having a first optical path length and a second beam having a second optical path length. The difference between the first optical path length and the second optical path length is based at least in part upon the incidence angle of the input signal. The reflective element reflects the first beam and the second beam such that the first beam interferes with the second beam to produce a first output signal and a second output signal. The first output signal comprises a first subset of wavelength channels from the input signal and the second output signal comprises a second subset of wavelength channels from the input signal.

Abstract: An interferometer receives an input optical signal and outputs a signal after changing at least the dispersion of said signal. At least portions of the interferometer are adjustable to adjust at least a first dispersion parameter. Examples of dispersion parameters which are adjustable include dispersion magnitude, center wavelengths and waveshapes or slopes. Preferably the dispersion in the output signal is substantially reduced or substantially eliminated, compared to the dispersion of the input signal. By providing for adjustability of one or more dispersion parameters, a dispersion compensator can be appropriately adjusted for use in a variety of applications.

Abstract: An optical wavelength router separates even and odd optical channels from an input WDM signal. The input beam is first converted into a pair of orthogonally-polarized beams. One of the beams is reflected by a mirror, while the other is reflected by a Fabry-Perot resonator (or etalon). The group delay of the reflected beams is strongly dependent on wavelength. The beams reflected from the resonator and mirror are combined and interfere in a birefringent element (e.g., a beam displacer or polarized beamsplitter) to produce a beam having mixed polarization as a function of wavelength. The polarized components of this beam are separated by a polarization-dependent routing element to produce two output beams containing complementary subsets of the input optical spectrum (e.g., even optical channels are routed to output port A and odd optical channels are routed to output port B).