Chiping Chen

US Patent:

6463200, Oct 8, 2002

Filed:

Oct 14, 1999

Appl. No.:

09/418344

Inventors:

Yoel Fink - Cambridge MA
Shanhui Fan - Somerville MA
Edwin Thomas - Natick MA
Chiping Chen - Needham MA
John Joannopoulos - Belmont MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G02B 616

US Classification:

385123, 385126

Abstract:

A device having at least one dielectric inner core region in which electromagnetic radiation is confined, and at least two dielectric outer regions surrounding the inner core region, each with a distinct refractive index. The outer regions confine electromagnetic radiation within the inner core region. The refractive indices, the number of outer regions, and thickness of the outer regions result in a reflectivity for a planar geometry that is greater than 95% for angles of incidence ranging from 0Â to at least 80Â for all polarizations for a range of wavelengths of the electromagnetic radiation. In exemplary embodiments, the inner core region is made of a low dielectric material, and the outer regions include alternating layers of low and high dielectric materials. In one aspect of the invention, the device is a waveguide, and in another aspect the device is a microcavity.

US Patent:

6603911, Aug 5, 2003

Filed:

Aug 1, 2002

Appl. No.:

10/210493

Inventors:

Yoel Fink - Cambridge MA
Shanhui Fan - Somerville MA
Edwin Thomas - Natick MA
Chiping Chen - Needham MA
John Joannopoulos - Belmont MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G02B 616

US Classification:

385123, 385126

Abstract:

A device having at least one dielectric inner core region in which electromagnetic radiation is confined, and at least two dielectric outer regions surrounding the inner core region, each with a distinct refractive index. The outer regions confine electromagnetic radiation within the inner core region. The refractive indices, the number of outer regions, and thickness of the outer regions result in a reflectivity for a planar geometry that is greater than 95% for angles of incidence ranging from 0Â to at least 80Â for all polarizations for a range of wavelengths of the electromagnetic radiation. In exemplary embodiments, the inner core region is made of a low dielectric material, and the outer regions include alternating layers of low and high dielectric materials. In one aspect of the invention, the device is a waveguide, and in another aspect the device is a microcavity.

US Patent:

6617775, Sep 9, 2003

Filed:

Oct 31, 2000

Appl. No.:

09/702948

Inventors:

Chiping Chen - Needham MA
Richard J. Temkin - Newton Centre MA

Assignee:

Electron Power Systems, Inc. - Acton MA

International Classification:

H01J 1726

US Classification:

3133591, 31323131, 313 62

Abstract:

Electrons are arranged so they circulate along a spiral path in a vacuum. The path has a hollow symmetrical shape which is defined by a surface of a toroid. The shape is controllable by a magnetic field and the electrons can be contained within the shape. A containing force can be created by external electromagnetic fields, ions within the vacuum, or by interactions between the orbiting electrons themselves. The contained electrons store energy for later retrieval.

US Patent:

7117133, Oct 3, 2006

Filed:

Jun 14, 2002

Appl. No.:

10/171725

Inventors:

Chiping Chen - Needham MA, US
Michael A. Shapiro - Marblehead MA, US
Evgenya I. Smirnova - Somerville MA, US
Richard J. Temkin - Newton MA, US
Jagadishwar R. Sirigiri - Cambridge MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G06F 17/50

US Classification:

703 2, 703 13, 703 17

Abstract:

A system and method for designing photonic band gap structures. The system and method provide a user with the capability to produce a model of a two-dimensional array of conductors corresponding to a unit cell. The model involves a linear equation. Boundary conditions representative of conditions at the boundary of the unit cell are applied to a solution of the Helmholtz equation defined for the unit cell. The linear equation can be approximated by a Hermitian matrix. An eigenvalue of the Helmholtz equation is calculated. One computation approach involves calculating finite differences. The model can include a symmetry element, such as a center of inversion, a rotation axis, and a mirror plane. A graphical user interface is provided for the user's convenience. A display is provided to display to a user the calculated eigenvalue, corresponding to a photonic energy level in the Brilloin zone of the unit cell.

US Patent:

7381967, Jun 3, 2008

Filed:

Jun 6, 2005

Appl. No.:

11/145804

Inventors:

Ronak J. Bhatt - Cambridge MA, US
Chiping Chen - Needham MA, US
Jing Zhou - Cambridge MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

B01D 59/44
H01J 49/00

US Classification:

250396ML, 313346 R, 3133631, 315501, 315505, 118 501, 136 58

Abstract:

The charged-particle beam system includes a non-axisymmetric diode forms a non-axisymmetric beam having an elliptic cross-section. A focusing element utilizes a magnetic field for focusing and transporting the non-axisymmetric beam, wherein the non-axisymmetric beam is approximately matched with the channel of the focusing element.

US Patent:

7538608, May 26, 2009

Filed:

Jun 17, 2004

Appl. No.:

10/870116

Inventors:

Chiping Chen - Needham MA, US
Richard J. Temkin - Needham MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H03F 3/58

US Classification:

330 43, 315 35, 315 393

Abstract:

A RF amplifier includes a RF input section for receiving a RF input signal. At least one single-sided slow-wave structure is associated with the RF interaction section. An electron ribbon beam that interacts with the RF input supported by the at least one single-sided slow-wave structure so that the kinetic energy of the electron beam is transferred to the RF fields of the RF input signal, thus amplifying the RF input signal. A RF output section outputs the amplified RF input signal.

US Patent:

7612346, Nov 3, 2009

Filed:

Jan 3, 2008

Appl. No.:

11/968833

Inventors:

Ronak J. Bhatt - Cypress TX, US
Chiping Chen - Needham MA, US
Jing Zhou - Woburn MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

B01D 59/44
H01J 49/00

US Classification:

250396ML, 250298, 250299, 250300, 315501, 315515, 313346 R, 3133631, 118 501, 136 58

Abstract:

The charged-particle beam system includes a non-axisymmetric diode forms a non-axisymmetric beam having an elliptic cross-section. A focusing element utilizes a magnetic field for focusing and transporting the non-axisymmetric beam, wherein the non-axisymmetric beam is approximately matched with the channel of the focusing element.

US Patent:

7619224, Nov 17, 2009

Filed:

Nov 15, 2007

Appl. No.:

11/940495

Inventors:

Chiping Chen - Needham MA, US
Thomas M. Bemis - Arlington MA, US
Ronak J. Bhatt - Cypress TX, US
Jing Zhou - Woburn MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H01J 49/10
H01J 1/50

US Classification:

250423R, 250424, 250423 F, 250396 R, 250396 ML, 25049221, 31511181, 31511141

Abstract:

A high-brightness, space-charge-dominated circular charged-particle beam system includes a flat circular emitter that emits charge particles to form a space-charge-dominated circular charged-particle beam. The space-charge-dominated circular charged-particle beam is emitted from the flat circular emitter with a uniform density and having a current emission being space-charge-limited, obeying the Child-Langmuir law. A diode includes at least one electrode at the flat circular emitter and at least one additional electrode that accelerates the charged particles. A beam tunnel is coupled electrically to at least one of the additional electrodes. An applied axisymmetric magnetic field focuses the space-charge-dominated circular charged-particle beam. A depressed collector collects the space-charge-dominated circular charged-particle beam.