David S Welch

US Patent:

6335941, Jan 1, 2002

Filed:

May 15, 2000

Appl. No.:

09/571711

Inventors:

Stephen G. Grubb - Fremont CA
David F. Welch - Menlo Park CA
Raymond Zanoni - Fremont CA

Assignee:

SDL, Inc. - San Jose CA

International Classification:

H01S 330

US Classification:

372 6, 359179, 359341

Abstract:

A high power laser optical amplifier system for material processing comprises multiple stage fiber amplifiers with rejection of propagating ASE buildup in and between the amplifier stages as well as elimination of SBS noise providing output powers in the range of about 10 J to about 100 J or more. The system is driven with a time varying drive signal from a modulated semiconductor laser signal source to produce an optical output allowing modification of the material while controlling its thermal sensitivity by varying pulse shapes or pulse widths supplied at a desire repetition rate via modulation of a semiconductor laser signal source to the system to precisely control the applied power application of the beam relative to the thermal sensitivity of the material to be processed. The high power fiber amplifier system has particular utility in high power applications requiring process treatment of surfaces, such as polymeric, organic, ceramic and metal surfaces, e. g. , material processing, surface texturing, heat treatment, surface engraving, fine micro-machining, surface ablation, cutting, grooving, bump forming, coating, soldering, sealing, surface diffusion and surface conversion to a compound.

US Patent:

6347007, Feb 12, 2002

Filed:

Jun 2, 2000

Appl. No.:

09/586405

Inventors:

Stephen G. Grubb - Fremont CA
David F. Welch - Menlo Park CA
Raymond Zanoni - Fremont CA

Assignee:

SDL, Inc. - San Jose CA

International Classification:

H01S 300

US Classification:

35933721, 359124, 3593372, 359347, 372 18

Abstract:

A high power laser optical amplifier system for material processing comprises multiple stage fiber amplifiers with rejection of propagating ASE buildup in and between the amplifier stages as well as elimination of SBS noise providing output powers in the range of about 10 J to about 100 J or more. The system is driven with a time varying drive signal from a modulated semiconductor laser signal source to produce an optical output allowing modification of the material while controlling its thermal sensitivity by varying pulse shapes or pulse widths supplied at a desire repetition rate via modulation of a semiconductor laser signal source to the system to precisely control the applied power application of the beam relative to the thermal sensitivity of the material to be processed. The high power fiber amplifier system has particular utility in high power applications requiring process treatment of surfaces, such as polymeric, organic, ceramic and metal surfaces, e. g. , material processing, surface texturing, heat treatment, surface engraving, fine micro-machining, surface ablation, cutting, grooving, bump forming, coating, soldering, sealing, surface diffusion and surface conversion to a compound.

US Patent:

6356574, Mar 12, 2002

Filed:

Jan 29, 1999

Appl. No.:

09/240361

Inventors:

Richard R. Craig - Victoria, CA
Robert L G. Waarts - Fremont CA
David F. Welch - Menlo Park CA
John G. Endriz - Belmont CA
Dirk J. Kuizenga - Sunnyvale CA
Steven Sanders - Palo Alto CA

Assignee:

SDL, Inc. - San Jose CA

International Classification:

H01S 30933

US Classification:

372 75, 372 50

Abstract:

A multistage optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources for pumping a single fiber laser pump source. A second level of redundancy deals with redundancy of a plurality of fiber laser pump sources for pumping a plurality of serially connected injection signal fiber amplifiers forming the multistage amplifier system. If one of fiber pump sources should fail, increased pumping power is available from the remaining fiber pump sources via their respectively connected amplifier stages. A third level of redundancy deals with redundancy in the employment of multiple single mode laser emitters on the same chip or bar sufficiently segmented and/or electrical isolated so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar.

US Patent:

6411323, Jun 25, 2002

Filed:

Dec 7, 2000

Appl. No.:

09/732477

Inventors:

Robert G. Waarts - Fremont CA
David F. Welch - Menlo Park CA

Assignee:

SDL, Inc. - San Jose CA

International Classification:

B41J 2700

US Classification:

347241, 347256, 385 37

Abstract:

Power scaling by multiplexing multiple fiber gain sources with different wave-lengths is useful in printing applications requiring higher optical powers to perform the printing function, such as through thermal inducement in thermal ablation, thermal fusion, thermal diffusion or thermal transfer. A marking system is disclosed using a plurality of laser sources operating at different wavelengths with their respective outputs coupled into a respective single mode fiber. At least one WDM combiner is coupled to receive and combine the laser source outputs into a single output. The combined power single output provides sufficient power intensity to induce thermal marking on a marking medium.

US Patent:

6433306, Aug 13, 2002

Filed:

Jun 2, 2000

Appl. No.:

09/585262

Inventors:

Stephen G. Grubb - Fremont CA
David F. Welch - Menlo Park CA
Raymond Zanoni - Fremont CA

Assignee:

JDS Uniphase Corp. - San Jose CA

International Classification:

B23K 2606

US Classification:

21912173, 21912168, 21912165

Abstract:

A high power laser optical amplifier system for material processing comprises multiple stage fiber amplifiers with rejection of propagating ASE buildup in and between the amplifier stages as well as elimination of SBS noise providing output powers in the range of about 10 J to about 100 J or more. The system is driven with a time varying drive signal from a modulated semiconductor laser signal source to produce an optical output allowing modification of the material while controlling its thermal sensitivity by varying pulse shapes or pulse widths supplied at a desire repetition rate via modulation of a semiconductor laser signal source to the system to precisely control the applied power application of the beam relative to the thermal sensitivity of the material to be processed. The high power fiber amplifier system has particular utility in high power applications requiring process treatment of surfaces, such as polymeric, organic, ceramic and metal surfaces, e. g. , material processing, surface texturing, heat treatment, surface engraving, fine micro-machining, surface ablation, cutting, grooving, bump forming, coating, soldering, sealing, surface diffusion and surface conversion to a compound.

US Patent:

6433920, Aug 13, 2002

Filed:

Sep 18, 2000

Appl. No.:

09/664986

Inventors:

David F. Welch - Menlo Park CA
Robert J. Lang - Pleasanton CA
Edward C. Vail - Menlo Park CA
Mehrdad Ziari - Pleasanton CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 300

US Classification:

359334, 3593371

Abstract:

An optical amplifier with a flattened wideband response is obtained by coupling counter-propagating pumping energy into an optical waveguide to cause Raman amplification in the optical waveguide, and by reflecting an amplified signal received from the optical waveguide into an output waveguide using a reflector having a spectral characteristic that is complementary to the spectral gain characteristic of the Raman amplification.

US Patent:

6580552, Jun 17, 2003

Filed:

Aug 27, 2001

Appl. No.:

09/940186

Inventors:

David F. Welch - Menlo Park CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 300

US Classification:

35934132, 359349

Abstract:

An optical amplifier includes a plurality of optical paths each carrying an optical signal and each including active optical fiber. A shared pump laser is coupled to the plurality of optical paths and provides pump power to the plurality of optical paths to individually amplify the optical signals. The plurality of optical paths includes input and output optical isolators and a coupler for coupling the pump power to the optical path. The active optical fiber is doped with an implant selected from the group of rare earth metals, erbium, ytterbium, and both ytterbium and erbium. A variable attenuator can be connected between the pump laser and the coupler of at least one of the plurality of optical paths or adjacent to the output isolator of one of the optical paths. Another optical amplifier serially couples optical signals to the optical path on a common gain media.

US Patent:

6603595, Aug 5, 2003

Filed:

Jun 26, 2002

Appl. No.:

10/185458

Inventors:

David F. Welch - Menlo Park CA
Robert J. Lang - Pleasanton CA
Edward C. Vail - Menlo Park CA
Mehrdad Ziari - Pleasanton CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 300

US Classification:

359334, 3593371

Abstract:

An optical amplifier with a flattened wideband response is obtained by coupling counter-propagating pumping energy into an optical waveguide to cause Raman amplification in the optical waveguide, and by reflecting an amplified signal received from the optical waveguide into an output waveguide using a reflector having a spectral characteristic that is complementary to the spectral gain characteristic of the Raman amplification.