Robert Alan Youngquist

US Patent:

47782374, Oct 18, 1988

Filed:

Jun 7, 1984

Appl. No.:

6/618032

Inventors:

Wayne V. Sorin - Stanford CA
Robert C. Youngquist - Mountain View CA
Cassius C. Cutler - Palo Alto CA
Herbert J. Shaw - Stanford CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

International Classification:

G02B 626

US Classification:

350 9615

Abstract:

A fiber optic saturable absorber for processing optical signals comprises an optical fiber from which a portion of the cladding is removed to form a facing surface. A light-absorbing substance having non-linear light-absorbing characteristics is applied to the facing surface such that a portion of the optical signal energy is transferred from the fiber to the substance where it is absorbed. The device selectively attenuates the optical signal and noise, and can be used to reduce pulse waveform distortion caused by pulse broadening and by amplification of system noise.

US Patent:

47922079, Dec 20, 1988

Filed:

May 15, 1987

Appl. No.:

7/050762

Inventors:

Herbert J. Shaw - Stanford CA
Robert C. Youngquist - Mountain View CA
Janet L. Brooks - Mountain View CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

International Classification:

G02B 602
G02B 530
G02F 111

US Classification:

350 9629

Abstract:

A fiber optic frequency shifter comprising two waveguides having different indices of refraction. In some embodiments the waveguides are two modes of propagation in one fiber. Plural distributed coupling ridges, or electrodes mounted adjacent piezoelectric materials, are independently driven to apply sinusoidally varying forces to the fiber. In some embodiments, the phase relationship of the driving signals for the electrodes or ridges is such that a travelling acoustic wave is launched in the fiber. In other embodiments, regions of stress in the fiber are created by an acoustic wave coupled into the fiber from a transducer coupled to an acoustic medium surrounding the fiber. The input carrier light is shifted in frequency by the frequency of the acoustic wave.

US Patent:

48011894, Jan 31, 1989

Filed:

Feb 22, 1988

Appl. No.:

7/161375

Inventors:

Herbert J. Shaw - Stanford CA
Robert C. Youngquist - Mountain View CA
Janet L. Brooks - Mountain View CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

International Classification:

G02B 626
G02B 530

US Classification:

350 9615

Abstract:

There is disclosed herein a fiber optic directional coupler for coupling light between two polarization modes. A highly birefringent fiber optic waveguide is positioned on a flat polished surface with either of the principal axes of birefringence oriented at an angle, preferably 45. degree. , to the vertical. A ridged block is then pressed down on the fiber. The ridges of the block have longitudinal axes transverse to the longitudinal axis of the fiber. The width of the ridge faces is one-half beat length, and the spacing between the ridges in also one-half beat length. The stressed regions caused by the ridges cause coupling of light traveling in one polarization mode into the other polarization mode by abrupt shifting of the axes of birefringence at the boundaries of the stressed regions.

US Patent:

47688513, Sep 6, 1988

Filed:

Jul 9, 1986

Appl. No.:

6/884871

Inventors:

Herbert J. Shaw - Stanford CA
Robert C. Youngquist - Mountain View CA
Janet L. Brooks - Mountain View CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

International Classification:

G02B 626
G01B 902

US Classification:

350 9615

Abstract:

A modal coupler, for coupling between first and second order modes of an optical fiber, comprises a single continuous strand of optical fiber, and a device for applying stress to the optical fiber at spaced intervals along the fiber. The stress deforms the fiber and abruptly changes the fiber geometry at the beginning and end of each stressed region. The change in fiber geometry causes coupling of light from the fundamental mode to the second order mode. The coupler, under certain conditions, exhibits polarization dependence, and thus, it may be utilized as a fiber optic polarizer. In addition, the device couples coherently, and may be used in interferometric systems.

Author:

Robert S. Youngquist

ISBN #:

0721653960

Author:

Robert S. Youngquist

ISBN #:

0721693237