Jing Tao Zhao, 43Amesbury, MA

6337991, Jan 8, 2002

Nov 5, 1997

08/964520

Yi-Qun Li - Tewksbury MA
Jing Zhao - Winchester MA

Corning Applied Technologies Corp. - Woburn MA

G01B 700

505161, 505238

Oxide thin films having a perovskite-like structure and undergoing a ferromagnetic phase transition with large temperature coefficients of resistance (TCRs) are disclosed. These can be useful materials for making thermistors, bolometers, infrared detectors and the like. These can be fabricated with a number of methods, preferably including metal oxide chemical vapor deposition, laser ablation and sputtering. In one embodiment, the oxides are based on a LaMnO with substitutions of Ca, Sr, Ba, Mn, and Pb for some of the La. The amounts can be varied to maximize the TCR or shift the temperature at which the maximum occurs. Methods of making such thin films are disclosed. In one embodiment, the high sensitivity films can be used in an array of micro-bolometers in an infrared camera.

6404538, Jun 11, 2002

Oct 24, 2000

09/695538

Qiushui Chen - Medford MA
Gary Y. Wang - Fremont CA
Paul Melman - Newton MA
Kevin Zou - Burlington MA
Hua Jiang - Mansfield MA
Run Zhang - Bedford MA
Jing Zhao - Winchester MA
Dean Tsang - Burlington MA
Feiling Wang - Medford MA

Corning Applied Technologies Corporation - Woburn MA

G02F 100

359323, 359239, 359251, 359322

An optical modulator is provided to control the intensity of a transmitted or reflected light. In a transmission mode, a separator splits arbitrarily polarized light into two polarization rays and one is made to travel a separate path from the other. A recombiner causes the two rays to recombine at an output unless an electro-optic phase retarder changes the polarization of the two rays, in which case, both of them miss the output by an amount which is a function of the voltage on the retarder. A normally-off version with low polarization mode dispersion is obtained by changing the orientation of the recombiner. A normally-on version with low polarization mode dispersion is obtained with a passive polarization direction rotator. Similar results can be obtained in a reflection mode where the input and output are on the same side of the modulator. Versions using a GRIN lens are particularly suited to modulation of light out of and back into fiber-optic cables.

6522456, Feb 18, 2003

May 4, 2001

09/848766

Qiushui Chen - Medford MA
Hua Jiang - Mansfield MA
Yingyin Zou - Burlington MA
Dean Tsang - Burlington MA
Paul Melman - Newton MA
Feiling Wang - Medford MA
Guanghai Jin - Boxborough MA
Jing Zhao - Winchester MA

Corning Applied Technologies, Inc. - Woburn MA
Corning Incorporated - Corning NY

G02F 100

359322, 359239, 359245, 359246, 359248, 359256, 359323

An apparatus and method for filtering an optical input is disclosed. In an illustrative embodiment, an optical input is split into polarization components along separate paths. The polarization components are then fed into a first electro-optic device that includes a set of electrodes across which a voltage is applied to adjust a wavelength transmission characteristic of the device. A section of the first device positioned between the electrodes preferably has a birefringence that is adjusted depending on the voltage applied across the electrodes. The adjusted components of the optical input are thereafter combined to produce an optical output. Accordingly, the optical input can be attenuated based on the voltage applied to electrodes of the first electro-optic device.

6577430, Jun 10, 2003

May 14, 2001

09/853713

Guanghai Jin - Woburn MA, 01801
Lei Zhang - Acton MA
Jing Zhao - Winchester MA

Guanghai Jin - Woburn MA

G02F 109

359280, 359281, 359320, 359324, 359484, 385 16, 385 22, 385 11, 385 18, 343756

The present invention provides improved optical switches in which no mechanical movement is required to direct optical pathways between plural fiber ports and light transmission is bi-directional. Advantageously, the inventive switches permit bi-directional light transmission. The inventive switches also incorporate light bending devices to allow two fibers to be coupled to the light beams using a single lens for compactness. In the inventive switch, an optical signal is spatially split into two polarized beams by a birefringent element, which passes through a polarization rotation device that comprises waveplates, walk-off elements, and an electrically controllable polarization rotator, and recombine into an output fiber, achieving polarization independent operation. The switches of the present invention rely on electro-magnetically or electro-optically switching the beam polarizations from one state to another to rapidly direct the light path.

6718082, Apr 6, 2004

Dec 18, 2001

10/017236

Jing Zhao - Winchester MA
Xianfeng Lin - Woburn MA

Agiltron, Inc. - Wilmington MA

G02B 626

385 16, 385 11, 385 15, 385 22, 385 36, 385 47, 398 45, 398 65, 398 86, 398152, 359494, 359495, 359496

The present invention provides an improved optical wavelength switch in which no mechanical movement is required to direct optical pathways between several fiber ports. The inventive three-fiber port device divides incoming optical signals into two subsets of spectra and selectively directs them into two output ports in response to an electrical control signal. In the inventive switch, an optical signal is spatially split into two polarized beams, by a birefringent element, which thereafter pass through a series polarization rotation elements and recombine into output fibers, achieving polarization independent operation. Advantageously, the inventive switch incorporates two-stage polarization rotations to improve isolation depth, as well as temperature and wavelength independence. The invention also incorporates light bending devices to allow two fibers to be coupled to the light beams via a single lens, thereby achieving small beam separation for compactness. Switches rely on electromagnetically or electro-optically switching the beam polarizations from one state to another to rapidly direct the light path.

7224860, May 29, 2007

Oct 8, 2004

10/962372

Jing Zhao - Winchester MA, US
Yongjun Shu - Arlington MA, US

G02B 6/27
G02B 6/35

385 17

Optical switches which take multiple incoming optical signals and switch them to multiple output ports to realize multiple working states. For example, in a four by four switch embodiment, twenty-four working states can be selected. These switches rely on magneto-optically or electro-optically switching the beam polarizations from one state to another to rapidly change the light path. An optical signal is spatially split into two polarized beams by a birefringent element. These beams pass through a series of polarization rotation elements and recombine into output fibers, achieving polarization independent operation. A polarization beam splitter may be used as the key element to establish multi-port switching. Light bending devices that allow two fibers to be coupled to the light beams using a single lens may be used to achieve small fiber separation for compactness.

7403677, Jul 22, 2008

Aug 30, 2005

11/216434

Jing Zhao - Winchester MA, US
Jin Guanghai - Boxborough MA, US
Shu Yongjun - Woburn MA, US

Agiltron, Inc. - Woburn MA

G02B 6/26
G02B 6/32
G02F 1/03

385 15, 385 33, 385 34, 385 35, 385 93, 359245, 359251, 359252, 359254, 359255, 359256, 359257, 359258, 359315, 359319, 359322, 359323

An apparatus and method to operate on a light beam by using a lens that collimates the light beam to a collimated beam with at least one cross-sectional dimension less than a critical dimension of 400 μm or less over a working range WR. The apparatus has a bulk electro-optic material of small thickness τ, e. g. , less than 300 μm positioned within working range WR and the collimated beam traverses it along its path. The apparatus has a voltage source for applying a low operating or drive voltage V, e. g. less than 400 V to the bulk electro-optic material for performing an operation on the collimated beam. The lens for collimating the light beam is a free-space collimator such as a graded index (GRIN) lens or preferably a C-lens. The apparatus is a versatile and scalable platform that can be employed in building various electro-optic devices.

7505192, Mar 17, 2009

May 7, 2007

11/800740

Jing Zhao - Winchester MA, US
Guanghai Jin - Boxborough MA, US
Yongjun Shu - Woburn MA, US

Agiltron, Inc. - Woburn MA

G02F 1/09

359282, 359281

An optical apparatus and methods for operating on a polarization state of a light beam using a compound tri-state non-reciprocal rotator having two Faraday rotators. A first Faraday rotator rotates the polarization state into one of two partially rotated states at angles +α, −α, where α=22. 5, and the second Faraday rotates the polarization state from one of the partially rotated states into one of three fully rotated states at angles +2α, 0, −2α. A polarization selection mechanism guides light in the three fully rotated states differently to enable various devices and different modes of operation. For example, the polarization selection mechanism can generate a tri-state output in the form of two distinct output beams corresponding to two of the three fully rotated states, and an overlapping pair of output beams obtained when the compound tri-state non-reciprocal rotator produces the third of the three fully rotated states. The various methods permitted by the invention permit simple and cost-effective multicasting switches and methods.