{"id":{"repo_id":"heriot-watt","oai_identifier":"oai:ros.hw.ac.uk:10399/2333"},"canonical_url":"https://search.dev.ndltd.org/etd/heriot-watt/oai:ros.hw.ac.uk:10399/2333","repository":{"repo_id":"heriot-watt","name":"Heriot-Watt University","base_url":"https://www.ros.hw.ac.uk/oai/request"},"display":{"title":"Efficient, high-power operation of CW Yb:YAG and Q-switched Nd:YAG planar waveguide lasers","abstract":"The planar waveguide gain medium o ers a good approach to creating a high- power lasers. Excellent thermal properties allow for lasers with good beam-quality and high-e ciency. A Neodymium doped YAG planar waveguide laser was actively Q-switched using a hybrid unstable resonator and acousto-optic modulator. A Yt- terbium doped YAG planar waveguide laser was side-pumped using two laser diode stacks with a total of 800 W incident pump power. The Nd:YAG planar waveguide laser has a core 200 um thick and was face pumped with ten laser diode bars. Q-switching was achieved through the use of a new hybrid unstable resonator con guration providing high-speed modulation of the laser cavity. The laser produced 100 W of average power with a pulse repetition rate of 100 kHz, giving 1 mJ pulses with 50 ns duration. Shorter 15 ns pulses were achieved with 4.5 mJ pulse energy at lower pulse repetition rates. The Yb:YAG planar waveguide laser has a 150 um core thickness, side pumped by two 430 W, six-bar diode laser stacks. Each diode stack has a custom phase- plate, correcting for collimation errors and lens aberrations. These gave a line focus matching the dimensions of the waveguide core with an incident intensity on each side of approximately 22 kWcm-2. Ray tracing of spontaneous emission within the waveguide core shows side facet angles of 7 and 20 were required to minimise ASE and parasitic oscillations within the waveguide core. A technique to image the uorescence from the Yb:YAG waveguide core has been developed. This technique allows for easy alignment of the pump lasers to the waveg- uide core and measurement of the pump intensity pro le throughout the planar waveg- uide. This technique showed single-sided pumping to follow Beer's law, and with double-sided pumping considerably improved the pump uniformity. A diode laser probe was used to measure the gain present within the waveguide. The small signal gain coe cient was shown to be 1 cm-1 with a uniform pro le across the width of the waveguide when pumped to saturation. This highlights the potential of operating the planar waveguide laser as an e cient ampli er. High-power high-e ciency operation of the Yb:YAG planar waveguide laser was achieved through the use of a hybrid stable waveguide resonator. Output power of 400 W was extracted in a multi-mode beam with a slope e ciency of 75%. This result represents the highest output power from a diode-pumped solid-state planar waveguide laser to date.","abstract_html":"The planar waveguide gain medium o ers a good approach to creating a high- power lasers. Excellent thermal properties allow for lasers with good beam-quality and high-e ciency. A Neodymium doped YAG planar waveguide laser was actively Q-switched using a hybrid unstable resonator and acousto-optic modulator. A Yt- terbium doped YAG planar waveguide laser was side-pumped using two laser diode stacks with a total of 800 W incident pump power. The Nd:YAG planar waveguide laser has a core 200 um thick and was face pumped with ten laser diode bars. Q-switching was achieved through the use of a new hybrid unstable resonator con guration providing high-speed modulation of the laser cavity. The laser produced 100 W of average power with a pulse repetition rate of 100 kHz, giving 1 mJ pulses with 50 ns duration. Shorter 15 ns pulses were achieved with 4.5 mJ pulse energy at lower pulse repetition rates. The Yb:YAG planar waveguide laser has a 150 um core thickness, side pumped by two 430 W, six-bar diode laser stacks. Each diode stack has a custom phase- plate, correcting for collimation errors and lens aberrations. These gave a line focus matching the dimensions of the waveguide core with an incident intensity on each side of approximately 22 kWcm-2. Ray tracing of spontaneous emission within the waveguide core shows side facet angles of 7 and 20 were required to minimise ASE and parasitic oscillations within the waveguide core. A technique to image the uorescence from the Yb:YAG waveguide core has been developed. This technique allows for easy alignment of the pump lasers to the waveg- uide core and measurement of the pump intensity pro le throughout the planar waveg- uide. This technique showed single-sided pumping to follow Beer's law, and with double-sided pumping considerably improved the pump uniformity. A diode laser probe was used to measure the gain present within the waveguide. The small signal gain coe cient was shown to be 1 cm-1 with a uniform pro le across the width of the waveguide when pumped to saturation. This highlights the potential of operating the planar waveguide laser as an e cient ampli er. High-power high-e ciency operation of the Yb:YAG planar waveguide laser was achieved through the use of a hybrid stable waveguide resonator. Output power of 400 W was extracted in a multi-mode beam with a slope e ciency of 75%. This result represents the highest output power from a diode-pumped solid-state planar waveguide laser to date.","abstract_has_math":false,"creators":["Thomson, Ian James"],"institution":"Heriot-Watt University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Baker, Professor Howard"],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-03","date_published":"2010-03","updated_at":"2026-07-24T02:31:07Z","subjects":[],"languages":["en"],"rights":["All items in ROS are protected by the Creative Commons copyright license (http://creativecommons.org/licenses/by-nc-nd/2.5/scotland/), with some rights reserved."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10399/2333","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Baker, Professor Howard"]},{"key":"dc:creator","label":"Author","values":["Thomson, Ian James"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2010-12-20T12:48:46Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2010-12-20T12:48:46Z"]},{"key":"dc:date.issued","label":"Date","values":["2010-03"]},{"key":"dc:publisher","label":"Institution","values":["Heriot-Watt University","Engineering and Physical Sciences"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["All items in ROS are protected by the Creative Commons copyright license (http://creativecommons.org/licenses/by-nc-nd/2.5/scotland/), with some rights reserved."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10399/2333"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The planar waveguide gain medium o ers a good approach to creating a high- power lasers. Excellent thermal properties allow for lasers with good beam-quality and high-e ciency. A Neodymium doped YAG planar waveguide laser was actively Q-switched using a hybrid unstable resonator and acousto-optic modulator. A Yt- terbium doped YAG planar waveguide laser was side-pumped using two laser diode stacks with a total of 800 W incident pump power. The Nd:YAG planar waveguide laser has a core 200 um thick and was face pumped with ten laser diode bars. Q-switching was achieved through the use of a new hybrid unstable resonator con guration providing high-speed modulation of the laser cavity. The laser produced 100 W of average power with a pulse repetition rate of 100 kHz, giving 1 mJ pulses with 50 ns duration. Shorter 15 ns pulses were achieved with 4.5 mJ pulse energy at lower pulse repetition rates. The Yb:YAG planar waveguide laser has a 150 um core thickness, side pumped by two 430 W, six-bar diode laser stacks. Each diode stack has a custom phase- plate, correcting for collimation errors and lens aberrations. These gave a line focus matching the dimensions of the waveguide core with an incident intensity on each side of approximately 22 kWcm-2. Ray tracing of spontaneous emission within the waveguide core shows side facet angles of 7 and 20 were required to minimise ASE and parasitic oscillations within the waveguide core. A technique to image the uorescence from the Yb:YAG waveguide core has been developed. This technique allows for easy alignment of the pump lasers to the waveg- uide core and measurement of the pump intensity pro le throughout the planar waveg- uide. This technique showed single-sided pumping to follow Beer's law, and with double-sided pumping considerably improved the pump uniformity. A diode laser probe was used to measure the gain present within the waveguide. The small signal gain coe cient was shown to be 1 cm-1 with a uniform pro le across the width of the waveguide when pumped to saturation. This highlights the potential of operating the planar waveguide laser as an e cient ampli er. High-power high-e ciency operation of the Yb:YAG planar waveguide laser was achieved through the use of a hybrid stable waveguide resonator. Output power of 400 W was extracted in a multi-mode beam with a slope e ciency of 75%. This result represents the highest output power from a diode-pumped solid-state planar waveguide laser to date."]},{"key":"dc:title","label":"Title","values":["Efficient, high-power operation of CW Yb:YAG and Q-switched Nd:YAG planar waveguide lasers"]}]}],"canonical_facts":{"dc:contributor.advisor":["Baker, Professor Howard"],"dc:creator":["Thomson, Ian James"],"dc:date.accessioned":["2010-12-20T12:48:46Z"],"dc:date.available":["2010-12-20T12:48:46Z"],"dc:date.issued":["2010-03"],"dc:description.abstract":["The planar waveguide gain medium o ers a good approach to creating a high- power lasers. Excellent thermal properties allow for lasers with good beam-quality and high-e ciency. A Neodymium doped YAG planar waveguide laser was actively Q-switched using a hybrid unstable resonator and acousto-optic modulator. A Yt- terbium doped YAG planar waveguide laser was side-pumped using two laser diode stacks with a total of 800 W incident pump power. The Nd:YAG planar waveguide laser has a core 200 um thick and was face pumped with ten laser diode bars. Q-switching was achieved through the use of a new hybrid unstable resonator con guration providing high-speed modulation of the laser cavity. The laser produced 100 W of average power with a pulse repetition rate of 100 kHz, giving 1 mJ pulses with 50 ns duration. Shorter 15 ns pulses were achieved with 4.5 mJ pulse energy at lower pulse repetition rates. The Yb:YAG planar waveguide laser has a 150 um core thickness, side pumped by two 430 W, six-bar diode laser stacks. Each diode stack has a custom phase- plate, correcting for collimation errors and lens aberrations. These gave a line focus matching the dimensions of the waveguide core with an incident intensity on each side of approximately 22 kWcm-2. Ray tracing of spontaneous emission within the waveguide core shows side facet angles of 7 and 20 were required to minimise ASE and parasitic oscillations within the waveguide core. A technique to image the uorescence from the Yb:YAG waveguide core has been developed. This technique allows for easy alignment of the pump lasers to the waveg- uide core and measurement of the pump intensity pro le throughout the planar waveg- uide. This technique showed single-sided pumping to follow Beer's law, and with double-sided pumping considerably improved the pump uniformity. A diode laser probe was used to measure the gain present within the waveguide. The small signal gain coe cient was shown to be 1 cm-1 with a uniform pro le across the width of the waveguide when pumped to saturation. This highlights the potential of operating the planar waveguide laser as an e cient ampli er. High-power high-e ciency operation of the Yb:YAG planar waveguide laser was achieved through the use of a hybrid stable waveguide resonator. Output power of 400 W was extracted in a multi-mode beam with a slope e ciency of 75%. This result represents the highest output power from a diode-pumped solid-state planar waveguide laser to date."],"dc:identifier.uri":["http://hdl.handle.net/10399/2333"],"dc:language.iso":["en"],"dc:publisher":["Heriot-Watt University","Engineering and Physical Sciences"],"dc:rights":["All items in ROS are protected by the Creative Commons copyright license (http://creativecommons.org/licenses/by-nc-nd/2.5/scotland/), with some rights reserved."],"dc:title":["Efficient, high-power operation of CW Yb:YAG and Q-switched Nd:YAG planar waveguide lasers"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T02:31:07Z"}