Thomas R Stone

US Patent:

48344745, May 30, 1989

Filed:

May 1, 1987

Appl. No.:

7/045991

Inventors:

Nicholas George - Pittsford NY
Thomas W. Stone - Rochester NY

Assignee:

The University of Rochester - Rochester NY

International Classification:

G02B 532
H01S 308
H01S 31055

US Classification:

350 365

Abstract:

Optical systems, using volume holographic elements (gratings) having geometries which tailor the spatio-temporal dispersion of the optical pulses for the system. The input optical pulse is characterized by a frequency variation across the temporal profile of the pulse. The various frequency components of this pulse are first dispersed by at least one grating which may be of the blazed reflection or holographic volume transmission type. The resultant dispersed light is then diffracted by a holographic volume grating which imparts the desired temporal dispersion characteristics to the pulse. The shape of the holographic element will vary according to the input pulse frequency profile as formed by varied chirping techniques. A grating stage may then be repeated, preferably with additional elements in mirror symmetry to the first or by retro-reflection, in order to recombine the spatially dispersed pulse components into an exiting pulse which may be of vastly compressed temporal profile. In optical dispersive delay lines, the grating geometry provides temporal dispersion which is a desired function of wavelength of the optical pulses.

US Patent:

47861240, Nov 22, 1988

Filed:

Apr 27, 1987

Appl. No.:

7/043124

Inventors:

Thomas W. Stone - Rochester NY
Nicholas George - Pittsford NY

Assignee:

University of Rochester - Rochester NY

International Classification:

G02B 532
G02B 518
G02F 111
G01B 902

US Classification:

350 37

Abstract:

Achromatic optical systems forming phase shifters and phase modulators are presented and shown to impart (temporal) phase-angle shifts in incoming waves which are independent of wavelength over extremely broad spectral ranges (achromatic or white light). Three major classes of achromatic phase shifters are described including the triangle, close cascade, and imaged grating configurations. When constructed utilizing volume holographic optical elements, very high diffraction efficiencies may be achieved over the large bandwidths used. These systems may similarly be utilized to impart achromatic frequency shifts and frequency modulations which are wavelength independent over extreme spectral ranges and usually do not disturb the spatial form of the input waves. These devices may be used in AC interferometers and allow such interferometers to be operated with white light. The devices are also useful in switching between spatial sine and cosine optical transforms in optical pattern recognition systems.

US Patent:

47521309, Jun 21, 1988

Filed:

Oct 24, 1986

Appl. No.:

6/922913

Inventors:

Nicholas George - Pittsford NY
Thomas W. Stone - Rochester NY

Assignee:

The University of Rochester - Rochester NY

International Classification:

G01J 318
H01S 308

US Classification:

356334

Abstract:

An optical system which provides wavelength tuning and which may be a spectrometer, monochromator or tunable laser uses a volume transmission diffraction element which is characterized by a periodic, spatial variation of refractive index or polarizability or other light transmission effecting parameter, and which is distributed throughout the volume of the element. The wavelength is tuned by (1) varying the angles of the incident and diffracted light symmetrically with respect to the periodic distribution in the element and/or (2) by varying the spatial period of the diffracting element's volume modulation distribution which is maintained symmetric with respect to fixed incident and diffracted beam angles.