Robert R Mcleod

US Patent:

6437916, Aug 20, 2002

Filed:

Dec 4, 2000

Appl. No.:

09/727439

Inventors:

Robert R. McLeod - Morgan Hill CA
Adam Cohen - Fremont CA

Assignee:

JDS Uniphase Corporation - Nepean

International Classification:

G02B 530

US Classification:

359499, 359494, 359497, 359900

Abstract:

The invention provides an optical system for use in a stable, temperature-insensitive birefringent crystal interferometer (BCI). The optical system includes a first block of light transmissive birefringent material having an input port and an output port, the material having in the spectral region of desired device operation a net retardance at a first temperature, and straining means for inducing a strain in one of the first block and a second block of light transmissive material optically coupled to the first block, the strain induced for maintaining the net retardance substantially unchanged from the net retardance at least a second other temperature. Advantageously, the optical system uses a single variety of crystal, which is cheaper, more robust, and has better performance than BCIs having two crystal varieties.

US Patent:

6545805, Apr 8, 2003

Filed:

May 16, 2001

Appl. No.:

09/855569

Inventors:

Xue Dong He - Cupertino CA
Robert R. McLeod - Morgan Hill CA
Hong-Wei Mao - San Jose CA
Qingdong Guo - Sunnyvale CA
Kuochou Tai - Fremont CA
Kok-Wai Chang - Los Altos CA

Assignee:

JDS Uniphase Corp. - San Jose CA

International Classification:

G02B 530

US Classification:

359497, 359237, 359238, 359239, 359279, 359495, 359496

Abstract:

Conventional retroreflection mirrors in the form of right angle prisms are quite sensitive to beam position and beam angle errors. Manufacturing and assembly tolerances are also a cause of concern in conventional devices. Accordingly, the present invention solves these aforementioned problems by providing a retroreflection device comprising: a beam director, preferably in the form of a Wollaston prism; a polarization rotator, preferably in the form of a quarter wave plate; and a flat reflective surface, such as a plane mirror. The device of the present invention is far less sensitive to beam angle alignment and is completely independent of the beam position. The present invention is particularly useful as a beam splitter for directing orthogonally polarized beams of light back along parallel paths in an interleaver apparatus.

US Patent:

6549664, Apr 15, 2003

Filed:

Jun 30, 1999

Appl. No.:

09/343933

Inventors:

Andrew J. Daiber - Palo Alto CA
Robert R. McLeod - Morgan Hill CA
Ray Snyder - San Francisco CA

Assignee:

Siros Technologies, Inc. - Davis CA

International Classification:

G06K 936

US Classification:

382232, 359 1, 359 3

Abstract:

A method for storing data in a holographic storage medium comprises the steps of dividing a bit stream of binary data into data groups, encoding the data groups as binary patterns, and storing the binary patterns holographically as data pages. Each binary pattern comprises channel bits, wherein the number of âoffâ channel bits is greater than the number of âonâ channel bits. To retrieve information from the storage medium, the medium is illuminated and resultant light signals are gathered. The light signals are converted to the binary patterns, and the binary patterns are converted to the data groups. Binary patterns stored in the storage medium only slightly perturb subsequent reading and writing of data, since the patterns have fewer âonâ channel bits than âoffâ channel bits.

US Patent:

6563779, May 13, 2003

Filed:

Jun 15, 2000

Appl. No.:

09/595433

Inventors:

Mark E. McDonald - Mountain View CA
Robert R. McLeod - Morgan Hill CA
Andrew J. Daiber - Palo Alto CA

Assignee:

Siros Technologies, Inc. - Davis CA

International Classification:

G11B 700

US Classification:

369103, 369118

Abstract:

A tracking error signal generation apparatus and method which utilizes confocal detection with a split detector and a differencing circuit for generation of tracking error signals. A first lens is positioned in the path of a light beam returning from an optical medium. A pinhole is positioned in the path of the light beam after the first lens and proximate to the focal plane of the first lens. A second lens is positioned in the path of the light beam after the pinhole, and a split detector, having equal halves is positioned in the path of the light beam after the second lens. A differencing circuit is operatively coupled to each of the halves of the split detector. In operation, a light beam is focused by an optical head onto a track in the optical medium, and the reflection of the beam from the optical medium is directed through the first lens, through the pinhole, through the second lens, and onto the split detector. When the focus of the light beam is centered on the track, the reflected light reaching the split detector is evenly distributed on the two halves of the detector, such that the differencing circuit will generate a tracking error signal (TES) having nominally a zero value. When the focus of the light beam is off-center with respect to the track, the reflected light received by detector is unevenly distributed on the two halves of the detector such that the differencing circuit generates a non-zero tracking error signal, which will be of positive or negative value depending upon the direction off-center of the light beam focus spot.

US Patent:

6614741, Sep 2, 2003

Filed:

Nov 13, 1998

Appl. No.:

09/192165

Inventors:

Lambertus Hesselink - Woodside CA
Robert R. McLeod - Morgan Hill CA
Sergei L. Sochava - Sunnyvale CA

Assignee:

Research Investment Network, Inc. - Irvine CA

International Classification:

G11B 700

US Classification:

369103, 3692751

Abstract:

Digital data bits are stored at storage locations at plural depths within a holographic medium of a holographic storage disk in the form of selective, localized alterations in a format hologram. Micro-localized regions of a reflection format hologram extending throughout the medium are deleted by focusing a high-power laser beam at desired storage locations. The deletion regions have a lower reflectivity than the surrounding parts of the format hologram. Tunable-focus storage and retrieval heads, as well as dynamic aberration compensators, are used for multi-depth access. Storage and retrieval may each be achieved with a single head.

US Patent:

6765665, Jul 20, 2004

Filed:

Oct 21, 2002

Appl. No.:

10/274804

Inventors:

Brian Lee Heffner - Los Altos CA
Robert R. McLeod - Morgan Hill CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G01J 100

US Classification:

356213, 356229, 398 9

Abstract:

The invention relates to a simple and relatively inexpensive way of determining the optical bit rate of an optical signal, which is based on the fact that different percentages of the signal will be transmitted through a narrow-band optical filter depending on the bit rate. Increasing the bit rate of an optical signal results in a broadening of the channel spectrum, therefore, if the optical filter is designed with a passband thinner than all (or all but one) of the channel widths, then signals with different bit rates will have distinctive amounts of transmitted light relative to the amount of input light. In the preferred embodiment the optical signal is divided into two sub-beams by a beam splitter, and one of the sub-beams is passed through the optical filter. The power of filtered sub-beam is compared to the power of the unfiltered sub-beam to provide a ratio, which is compared to one or more predetermined values indicative of the bit rate. The optical filter is preferably a Fabry-Perot etalon with a periodic response tuned to the ITU grid.

US Patent:

7031610, Apr 18, 2006

Filed:

Jun 3, 2002

Appl. No.:

10/160636

Inventors:

Tokuyuki Honda - Sunnyvale CA, US
Robert R. McLeod - Morgan Hill CA, US

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G02B 6/30

US Classification:

398 85, 385 24, 385 37

Abstract:

A diffraction-compensated WDM (wavelength division multiplexer) uses TTFs (thin film filters) as concave mirrors. The WDM has a plurality of filter elements for guiding the optical signal along a predetermined optical path, each filter element being transparent to a predetermined wavelength range and including compensating means for at least partially compensating for diffraction of the optical signal. Each filter element has a thin film coated on a substrate, and the compensating means is a curved surface of each thin film. The WDM is more robust than prior art WDM devices using flat TTFs.

US Patent:

7035505, Apr 25, 2006

Filed:

Jul 22, 2004

Appl. No.:

10/896779

Inventors:

Jinxi Shen - San Ramon CA, US
Robert R. McLeod - Boulder CO, US
Douglas E. Crafts - San Jose CA, US
Barthelemy Fondeur - Mountain View CA, US
Yong Ding - Shanghai, CN
Pang-Chen Sun - San Diego CA, US

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G02B 6/28
H04B 10/00

US Classification:

385 24, 398135

Abstract:

An apparatus for monitoring an input optical signal at a plurality of distinct optical frequencies is disclosed wherein a demultiplexing arrayed waveguide grating (AWG) having a plurality of M>1 Vernier input ports is disposed between an optical switch and a photodiode array coupled to the output ports of the AWG. In operation, the optical switch sequentially provides the input optical signal into each of the Vernier ports, and signals detected by photodiodes are stored in a memory unit. The apparatus is capable of monitoring the input optical signal with a frequency step which is M times smaller than a frequency spacing between the AWG transmission bands, and obtain M frequency-resolved readings from each photodiode.