Robert C Burnham

US Patent:

43027296, Nov 24, 1981

Filed:

May 15, 1979

Appl. No.:

6/039424

Inventors:

Robert D. Burnham - Los Altos Hills CA
Donald R. Scifres - Los Altos CA
William Streifer - Palo Alto CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01S 319

US Classification:

331 945H

Abstract:

A solid state laser in which transverse mode control is achieved by a layer of non-uniform thickness adjacent the laser active region and longitudinal mode control is achieved by a periodic structure formed in the laser substrate. The layer of non-uniform thickness is provided by forming the layer on a channeled substrate, and the teeth of the periodic structure extend in a direction transverse to the direction of the channel.

US Patent:

43096700, Jan 5, 1982

Filed:

Sep 13, 1979

Appl. No.:

6/075381

Inventors:

Robert D. Burnham - Los Altos Hills CA
Donald R. Scifres - Los Altos CA
William Streifer - Palo Alto CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01S 319

US Classification:

331 945H

Abstract:

Improved lateral carrier and optical confinement is achieved in heterostructure diodes and lasers having a Fabry-Perot cavity transverse to the plane of the p-n junction of the device. Structural features during fabrication improve carrier confinement to the active region in the established optical cavity. Current confinement means is also fabricated above and below the active region to concentrate the current density to the active region in the optical cavity and thereby improve the overall gain of the device. Such confinement also enhances optical confinement along the cavity. Several reflector structures are disclosed for employment at the cavity ends to provide optical feedback.

US Patent:

39545342, May 4, 1976

Filed:

Oct 29, 1974

Appl. No.:

5/518335

Inventors:

Donald R. Scifres - Los Altos CA
Robert D. Burnham - Los Altos Hills CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01L 750

US Classification:

156 7

Abstract:

A structure for providing arrays or individual hemispherical diodes and methods of producing the diodes. When the diode array is to be part of a configuration utilizing a substrate, the substrate is selected to have radiation transparency, a lower refractive index, and lattice constant and lattice structure similar to that of a crystal layer grown in hemispheres formed in the substrate. When the diode array is to be removed from the substrate, a material that can be preferentially etched is grown between the hemispheres formed in the substrate and the grown crystal layer that is to have light emitting areas.

US Patent:

44334176, Feb 21, 1984

Filed:

May 29, 1981

Appl. No.:

6/268596

Inventors:

Robert D. Burnham - Palo Alto CA
Donald R. Scifres - Los Altos CA
William Streifer - Palo Alto CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01S 319

US Classification:

372 45

Abstract:

In a semiconductor injection laser with a nonplanar pattern in the substrate, growth of the plurality of layers comprising the laser structure is accomplished in vapor phase epitaxy to produce a lateral spatial thickness variation (LSTV) in the active region of the laser. The LSTV profile is one of or combination of the profiles disclosed in FIG. 2, producing an effective, although small, lateral refractive index variation in the active region, thereby permitting the maintenance of the lowest order transverse mode along the plane of the active region.

US Patent:

40064328, Feb 1, 1977

Filed:

Oct 15, 1974

Appl. No.:

5/515120

Inventors:

William Streifer - Palo Alto CA
Donald R. Scifres - Los Altos CA
Robert D. Burnham - Los Altos Hills CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01S 319
H01S 3081

US Classification:

331 945C

Abstract:

A heterojunction diode laser which produces a highly collimated, polarized light beam perpendicular to the plane of the PN junction of the laser rather than through cleaved end faces in the plane of the PN junction. The diode laser includes a periodic structure which is buried at a heterojunction interface and in contact with a light waveguide layer. The periodic structure acts to produce the feedback necessary for lasing. If the spacing of the teeth of the periodic structure are an integer number of wavelengths of the light photons produced in the laser, the light beam exits at an angle perpendicular to the plane of the PN junction. If a tooth spacing is chosen that is not equal to an integer number of wavelengths of the light photons produced in the laser, the light beam may emerge from the diode at an angle other than the normal with the specific angle determined by the particular tooth spacing. To increase output intensity, the ends of the laser perpendicular to the plane of the PN junction and parallel to the teeth of the periodic structure may be cleaved and coated with a highly light reflective film.

US Patent:

47275570, Feb 23, 1988

Filed:

Dec 30, 1985

Appl. No.:

6/814863

Inventors:

Robert D. Burnham - Palo Alto CA
Robert L. Thornton - East Palo Alto CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01S 319

US Classification:

371 50

Abstract:

Phased array semiconductor lasers provide fundamental or preferred 1st supermode operation wherein fabrication is accomplished by a single, continuous fabricating process, e. g. MO-CVD or MBE, followed by impurity induced disordering (IID), e. g. utilization of the impurity diffusion technique or the implant/anneal technique as now known in the art. The laser comprising this invention is provided with a relatively thin active region or with a single or multiple quantum well structure in the active region and is fabricated by forming spatially disposed impurity induced disordering regions extending into or penetrating through the active region to form spatially disposed regions capable of providing higher gain compared to adjacent regions not experiencing impurity induced disordering. The adjacent regions without impurity induced disordering contain unspoiled regions that provide high real index waveguiding compared to the adjacent disordered regions with the diffusions in the disordered regions have higher conductivity properties compared to the remaining ordered regions and are, therefore, more efficiently pumped electrically. As a result, disordered regions form alternating higher gain regions offset between regions of nondisordered waveguide regions having higher real index waveguiding properties but lower gain properties, thereby fulfilling the conditions necessary to provide fundamental or preferred 1st supermode operation.

US Patent:

39835090, Sep 28, 1976

Filed:

Apr 25, 1975

Appl. No.:

5/572475

Inventors:

Donald R. Scifres - Los Altos CA
Robert D. Burnham - Los Altos CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01S 319

US Classification:

331 945H

Abstract:

A laser having layers of a first material interleaved with layers of a second material with the first material having a different index of refraction and bandgap than those of the second material. The thicknesses of the layers of the first and second materials satisfy the relationship t = m. lambda. /2n where m is the laser mode and n is the index of refraction of the material, such that the right and left going waves of the light produced by the layers of the first material when the laser is pumped are coupled and reinforced in a coherent manner by the layers of the second material such that reflections from the second material are in phase, thus allowing laser operation in the absence of discrete end mirrors.

US Patent:

44487975, May 15, 1984

Filed:

Feb 4, 1981

Appl. No.:

6/231556

Inventors:

Robert D. Burnham - Los Altos Hills CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H01L 21203
H01L 21205

US Classification:

427 8

Abstract:

Various mask configurations and techniques for their employment in a chemical vapor deposition system are disclosed. These masks can be utilized in the fabrication of semiconductor devices. The masks have at least one aperture therein and may be either removed after device processing or formed as an integral part of the semiconductor device being fabricated. In either case, semiconductor devices can be formed with one or more layers characterized by desired spatial variations in their thickness and/or contour. The integral masking techniques provide for incorporated self alignment which simplifies device processing. The fabrication of semiconductor injection lasers are disclosed as examples of applications of the masking techniques.