Patent application number | Description | Published |
20090135473 | MODIFIED MICHELSON DELAY LINE INTERFEROMETER - In an optical etalon with a fixed FSR determined by the cavity length, the time delay is adjusted by an etalon surface coating. The proper cavity length is chosen to achieve a desired FSR, and the coating is independently selected to obtain a desired time delay. | 05-28-2009 |
20090213468 | MICHELSON-INTERFEROMETER-BASED DELAY-LINE INTERFEROMETERS - An interferometer includes a means for splitting, at a splitting location, an input light beam into a first beam and a second beam; and means for recombining, at a recombination location, the first beam and the second beam. The interferometer is designed such that the first beam will travel a first optical path length (OPL) from the splitting location to the recombination location, and the second beam will travel a second OPL from the splitting location to the recombination location and such that when the input light beam has bean modulated at a data rate comprising a time interval, then the difference in optical path lengths between the first OPL and the second OPL is about equal to the time interval multiplied by the speed of light. | 08-27-2009 |
20090279181 | CO-PACKAGE DQPSK DEMODULATOR BY MICHELSON INTERFEROMETER - An interferometer includes a means for splitting, at a splitting location, an input light beam into a first beam and a second beam; and means for recombining, at a recombination location, the first beam and the second beam. The interferometer is designed such that the first beam will travel a first optical path length (OPL) from the splitting location to the recombination location, and the second beam will travel a second OPL from the splitting location to the recombination location and such that when the input light beam has been modulated at a data rate comprising a time interval, then the difference in optical path lengths between the first OPL and the second OPL is about equal to the time interval multiplied by the speed of light. | 11-12-2009 |
20110134532 | Modified Michelson delay-line interferometer - In an optical etalon with a fixed FSR determined by the cavity length, the time delay is adjusted by an etalon surface coating. The proper cavity length is chosen to achieve a desired FSR, and the coating is independently selected to obtain a desired time delay. | 06-09-2011 |
20110211194 | OPTICAL SPECTRUM ANALYZER WITH CONTINUOUSLY ROTATING TUYNABLE FILTER - An optical spectrum analyzer is implemented with a detector combined with a tunable filter mounted on a stage capable of 360-degree rotation at a constant velocity. Because of the constant rate of angular change, different portions of the input spectrum are detected at each increment of time as a function of filter position, which can be easily measured with an encoder for synchronization purposes. The unidirectional motion of the mirror permits operation at very high speeds with great mechanical reliability. The same improvements may be obtained using a diffraction grating or a prism, in which case the detector or an intervening mirror may be rotated instead of the grating or prism. | 09-01-2011 |
20110317170 | WEDGE PAIR FOR PHASE SHIFTING - The invention provides a wedge pair suitable for use in interferometers. The wedge pair produces a phase shift between beams of light propagating in the interferometer. The invention includes a wedge pair and a mechanism for translating a first wedge of the pair with respect to a second wedge of the pair, where the first wedge has the same wedge angle and material of the second wedge and where the vertex of the first wedge and the vertex of the second wedge are pointed in opposite directions. | 12-29-2011 |
20120257279 | GRATING BASED TUNABLE FILTER - In a grating based tunable filter, an input beam that includes multiple wavelengths is directed into an input fiber of a circulator. The beam is collimated and then is reflected by a rotationally actuated mirror. The beam is then magnified and propagates onto and through a transmission diffraction grating which causes the different wavelengths of the transmitted beam to deflect into different angles. The wavelengths propagate onto and are reflected by a mirror and only a small portion of the wavelength spectrum of the transmitted beam will be reflected back along the incoming path and then propagate to the output fiber | 10-11-2012 |
20120269482 | SINGLE-PACKAGE DUAL OPTICAL-FUNCTION DEVICE - A four-fiber collimator is coupled to the optics of a single interleaver to produce the functionality of two co-packaged interleavers. Two fibers of the collimator are coupled to the core optics of a single interleaver to produce two pairs of output beams. The other two fibers of the collimators are coupled to receive the reflection output beams. The geometry of the optical fibers in the bundle is controlled to produce interleaver outputs with no offset. In another embodiment two fibers of the four-fiber collimator are coupled as inputs to and the other two fibers as outputs from a Fabry-Perot etalon. The geometry of the fibers and the focal length of the collimator are controlled to produce two outputs with peaks offset by a predetermined amount. | 10-25-2012 |
20130077171 | TUNABLE INTERFERENCE FILTER WITH SHAPING PRISMS - A conventional interference tunable filter is combined with a pair of shaping prisms to enlarge the circular input beam in the direction orthogonal to the direction of beam propagation and to the axis of rotation of the tunable filter. The degree of expansion is tailored to minimize the walk-off losses produced by successive reflections in the cavity of the tunable filter. By appropriately sizing the enlargement, the substantially elliptical beam produced by the shaping prisms encompasses sufficient reflected beams after passing through the tunable filter to produce substantially the same filter output that in a conventional filter would require a materially larger input beam. The input beam is preferably first converted to two parallel beams of the same polarization state. Both beams are then expanded by the prisms and processed by the tunable filter. | 03-28-2013 |
20130094087 | TUNABLE FILTER USING A WAVE PLATE - Tunable filters are provided that have transmittances that are independent of the polarization state of an incident beam. The tunable filters include an interference bandpass filter positioned to transmit an input beam of light to produce transmitted light. A wave plate is positioned to rotate the polarization of the transmitted light and a reflector is positioned to reflect the rotated light so that it propagates through the wave plate a second time and then passes through the interference filter a second time to produce second transmitted light. | 04-18-2013 |
20130128907 | Coherent Micro-mixer - A coherent micro-mixer provides a 6-port device having two input ports four output ports. A signal light wave is input into one input port and a reference light wave is input into another input port. The four outputs from the output ports combine to produce interference between the two input light beams, with various relative phase shifts. | 05-23-2013 |
20130155515 | STACKABLE NARROWBAND FILTERS FOR DENSE WAVELENGTH DIVISION MULTIPLEXING - A plane-parallel optical window is the spacer of single-cavity filters in the stack used for DWDM applications. Highly reflective quarter-wave stacks are deposited on each side of the optical window and the single-cavity structure so obtained is diced to produce a plurality of filters. Because the single-cavity structure has the same thickness over the entire window area and the quarter-wave-stack deposition process is carried out throughout under the same conditions, each single-cavity filter fabricated from the optical window has the same transmission wavelength and is therefore readily stackable for DWDM applications. Alternatively, an optical window with a thickness equal to one half that required for the spacer of a single-cavity filter is coated on a single side. The window is then divided in multiple identical components that can be combined in pairs by placing them in optical contact so as to form individual single-cavity filters with the same transmission wavelength. | 06-20-2013 |
20130279006 | STACKABLE NARROWBAND FILTERS FOR DENSE WAVELENGTH DIVISION MULTIPLEXING - A plane-parallel optical window is the spacer of single-cavity filters in the stack used for DWDM applications. Highly reflective quarter-wave stacks are deposited on each side of the optical window and the single-cavity structure so obtained is diced to produce a plurality of filters. Each single-cavity filter so fabricated from the optical window has the same transmission wavelength and is therefore readily stackable for DWDM applications. Alternatively, an optical window with a thickness equal to one half that required for the spacer of a single-cavity filter is coated on a single side. The window is then divided in multiple identical components that can be combined in pairs by placing them in optical contact so as to form individual single-cavity filters with the same transmission-peak wavelength. The transmission peak of the filter can be fine tuned by controlling the temperature of the solid spacer material. | 10-24-2013 |
20140125975 | OPTICAL SPECTRUM ANALYZER WITH CONTINUOUSLY ROTATING TUNABLE FILTER - An optical spectrum analyzer is implemented with a detector combined with a tunable filter mounted on a stage capable of 360-degree rotation at a constant velocity. Because of the constant rate of angular change, different portions of the input spectrum are detected at each increment of time as a function of filter position, which can be easily measured with an encoder for synchronization purposes. The unidirectional motion of the mirror permits operation at very high speeds with great mechanical reliability. The same improvements may be obtained using a diffraction grating or a prism, in which case the detector or an intervening mirror may be rotated instead of the grating or prism. | 05-08-2014 |
20140176956 | Super-Steep Step-Phase Interferometer - Step-phase interferometers are provided for use as optical interleavers/de-interleaver for optical communication. High data rates require a wide band-width to pass the high-speed modulated optical spectrum, and further require a wide stop-band to reject the signal from adjacent channels. The present interferometers provide a steep slope at the transition from the passband to the adjacent stop-band, thereby enlarging the width of both the pass-band and stop-band. | 06-26-2014 |
20140209795 | HIGH RESOLUTION FAST TUNABLE FILTER USING A TUNABLE COMB FILTER - High resolution fast tunable optical filters are described such that each filter includes a tunable single-peak narrow-bandwidth (SPNB) filter and a tunable etalon in tandem with the tunable SPNB filter, where the bandwidth of the tunable SPNB filter is less than the free spectral range (FSR) of the tunable etalon. | 07-31-2014 |
20140211314 | EFFICIENCY OF A DEEP GRATING - Several techniques are provided to reduce the spurious reflection generated at the exit surface of a transmission grating. In one embodiment the exit surface of the grating is not parallel with the entrance surface. In another embodiment, the first and second surfaces of the grating are parallel and a second substrate is attached to the second surface of the grating. The second substrate has an entrance surface and an exit surface having at least a wedge angle relative to the entrance surface. In another embodiment, a second substrate is fixedly connected to the second surface of a parallel plate grating, where the second substrate has an entrance surface and an exit surface. The exit surface is curved such that it will be about normal to a beam transmitted over a range of angels of incidence onto the grating region. | 07-31-2014 |