Science Center 208
Ph.D., M.S., Boston College
B.S., University of Science and Technology of China
Novel ceramic materials for microchip and high power ceramic lasers:
Ceramic laser materials have recently received a lot of attentions because they are potentially great candidates for high-efficiency microchip or high power lasers. Contrast to popular single-crystal laser materials such as the rare-earth ion Nd doped single crystal YAG, ceramic materials are easy to be fabricated into large size and can accommodate high rare-earth ion (laser ion) concentrations. The first ceramic laser output was obtained in 1995 in Nd:YAG, and the first Yb:Y2O3 ceramic laser was just demonstrated in April 2003. To make ceramic lasers possible, the ceramic materials have to be made highly transparent with very low porosity and scattering loss. Recently, my students and I are working on a new kind of transparent ceramic materials, for example: Er-doped Pb-La-Zr-Ti-O (PLZT), for possible high-efficiency microchip or high-power laser applications. We concentrate on optical studies of this newly developed rare-earth ion doped PLZT and other lead-based ceramic materials. Our studies can provide crucial information for promising applications in new optical devices including PLZT ceramic lasers. This research has being supported by National Science Foundation and Wheaton Research Partnership Program.
Rare-earth ion doped laser crystals:
The most prominent rare earth ion in laser applications is trivalent neodymium (Nd) ion, which yields strong emission at wavelengths around 0.9, 1.0 and 1.3 micon when doped in a variety of hosts. Crystals with garnet structure are popular laser hosts for Nd ions. For example, the single crystal Nd:YAG has served over forty years as the most important solid-state laser material. Fluoride crystals are also found to be good hosts for Nd ions such as Nd:YLF. The Nd lasers have found many important applications such as laser radar and remote sensing. One of the recent efforts in NASA is to develop Nd laser systems that can produce a laser line at 0.94 micron for remote sensing of water vapor (H2O) in the atmosphere because water has a strong absorption line right at 0.94 micron. It is crucial to know how the Nd line positions and widths change with the host and temperature for efficient and effective Nd laser applications. The work on Nd doped laser crystals is to investigate thermal line position tuning (shift) and broadening of the Nd luminescence lines in different host crystals, focusing on garnet and fluoride hosts. Most of the crystals used in the study were provided by NASA.
Upconversion energy transfer processes in laser materials:
Upconversion phenomena have been studied actively in rare-earth ion doped laser solids. Typical rare-earth ions that are good for upconversion are Er, Tm, Ho, Pr, and Nd ions. The rare-earth ion Yb is often co-doped with some of these ions because it can help absorb energy efficiently and enhance the upconversion process. One of the most important applications of upconversion is to make upconversion lasers, which generally emit light that has higher photon energy than the pump photon energy. The research is to study the temperature and concentration dependence of upconversion processes in rare-earth ion doped laser solids, including single crystals and ceramics.
My research involves intensive experimental work, including the measurement of photoluminescence, absorption, transmission, reflectance, excitation, and lifetime over a wide range of temperatures. Measurement equipment includes lasers and other light sources from UV to IR, monochromators, spectrographs, light detectors, electronics, and computer date acquisition system.
My research has been supported by National Science Foundation, NASA, Air Force Office of Scientific Research, Research Corporation, Wheaton College, as well as industrial partners.
Physics at all levels for majors and non-majors.
Xuesheng Chen, B. Di Bartolo, Norman P. Barnes, and Brian M. Walsh, ˙gThermal tuning and broadening of the spectral lines of trivalent neodymium in laser crystals,˙h physica status solidi, submitted, expect to be published in 2004.
B. Di Bartolo and Xuesheng Chen, “Thermal Effects on the Spectral Characteristics of Laser Solids,” Journal of Applied Physics, submitted, expect to be published in 2004.
Xuesheng Chen, K. Li, K. Zou, R. Zhang, H. Jiang, G. Ozen, and B. Di Bartolo, “Novel Opto-Ceramic Materials for Microchip and High Power Ceramic Lasers,” accepted, The 2003 Fall Meeting of Materials Research Society, Boston, USA, December 1-5, 2003.
Xuesheng Chen, “Rare Earth Ion Doped Ceramic Laser Materials,” lecturer, Frontiers of Optical Spectroscopy, a NATO Advanced Institute, the International School of Atomic and Molecular Spectroscopy, Erice, Sicily, Italy, May 16 – June 1, 2003.
Charlotte Wong ’05 and Xuesheng Chen, “Concentration Dependence of Transmission of Er-doped Laser Crystals,” presented at The 2002 Fall Meeting of New England Section of American Physical Socity, 25-27 October 2002, Bridgewater State College, Bridgewater, MA.
Leanne Lortie ’06 and Xuesheng Chen, “Absorption Studies of the Er Ion Doped PLMNT and PLZT,” presented at the 2002 Fall Meeting of New England Section of American Physical Socity, 25-27 October 2002, Bridgewater State College, Bridgewater, MA.
Xuesheng Chen, “Thermal Tuning and Broadening of the Spectral Lines in Nd Laser Crystals,” a lecture given at the International School of Atomic and Molecular Spectroscopy – Workshop on The Status and Prospects of Luminescence Research, Erice-Sicily, Italy, 7-13 July 2002.
Book: “Advances in Energy Transfer Processes”, edited by B. Di Bartolo and Xuesheng Chen, World Scientific Publishing Company, November 2001.
Xuesheng Chen, “Upconversion Phenomena with Laser Applications,” in Advances in Energy Transfer Processes, ed. B. Di Bartolo and Xuesheng Chen, published by World Scientific Publishing Company, November 2001.
Xuesheng Chen, “Concentration and Temperature Dependence of Basic Luminescence Processes,” a lecture given at the International School of Atomic and Molecular Spectroscopy: Spectroscopy of Systems with Specially Confined Structures. Erice-Sicily, Italy, June 15-30, 2001.
B. Di Bartolo and Xuesheng Chen, “Thermal Effects on the Spectral Characteristics of Laser Solids,” a talk given at the 198th Meeting of The Electrochemical Society, 22-27 October 2000, Phoenix, Arizona, USA.
Xuesheng Chen and B. Di Bartolo, “Thermal Effects on Rare-Earth Spectra in Solids,” a lecture given at the International School of Atomic and Molecular Spectroscopy, 13th Workshop: Advanced Topics in Luminescence Spectroscopy, 23-29 July 2000, Erice, Sicily, Italy.
Xuesheng Chen and B. Di Bartolo, “Temperature Effects on the Spectra of Nd-doped Crystals,” a lecture given at the 2nd International Symposium on Laser, Scitillator and Nonlinear Optical Materials ˙ã Photonic Materials for the 21st Century, May 28-31, 2000, Lyon, France.
Liberty Gunter ’00, Carol McGeoch ’01, and Xuesheng Chen, “Spectroscopic Studies on the Erbium-doped Laser Materials YSGG:Er and GGG:Er at Different Temperatures,” presented at the 2000 Spring Meeting of the New England Section of American Physical Society, April 14-15, 2000, Rhode Island College, Providence, RI,
Xuesheng Chen and B. Di Bartolo, “Thermal Effects on the Spectra of Rare Earth Ions in Solids,” a talk given at the 30th Winter Colloquium on the Physics of Quantum Electronics. January 9-12,2000, Snowbird, Utah.
Xuesheng Chen, Timothy Nguyen ’00 *, Qui Luu ’00 *, and B. Di Bartolo, “Concentration Dependence of Visible Up-Conversion Luminescence in the Laser Crystal Gd3Ga5O12 Doped with Erbium,” Journal of Luminescence, Vol.85, 2000, p295-299.
Jianjun Zheng, Yalin Lu, and Xuesheng Chen, Mark Cronin-Golomb, and Jing Zhao, “Photoluminescence in Erbium-doped Pb(Mg1/3Nb2/3)3-PbTiO3 Thin Films,” Applied Physics Letters, 29 November 1999.
Xuesheng Chen, Timothy Nguyen ’00*, Qui Luu ’00*, and B. Di Bartolo, “Green and Red Luminescence of YSGG:Er under Up-conversion and Regular Excitation at Different Er Concentrations,” Journal of Luminescence, Vol.83-84, 1999, p471-475.
Xuesheng Chen and B. DiBartolo, “Thermal Shift and Broadening of Spectral Lines in Nydymium Doped Garnets,” Luminescent Materials, Vol.560, 1999.
Xuesheng Chen and B. DiBartolo, “Effects of the Ion-Phonon Interaction on Line Broadening and Shift in Rare-Earth-Ion Doped Laser Crystals,” a talk given at the International Workshop on Advances on Solid State Luminescence Spectroscopy, Erice, Italy, 22-28 June 1998.
Timothy Nguyen ’00*, Qui Luu ’00* and Xuesheng Chen, “Optical Properties and Upconversion Luminescence of Er3+ Doped GGG Laser Crystals,” the 1998 New England Section Meeting of the American Physical Society, 3-4 April 1998, Clark University, MA; the abstract was published in Bulletin of the American Physical Society, Vol.48, April 1998.
Qui Luu ’00*, Timothy Nguyen ’00* and Xuesheng Chen, “Luminescence of YSGG:Er3+ at Two Different Erbium Concentrations,” the Spring 1998 New England Section Meeting of the American Physical Society, April 3-4, 1998, Clark University, MA; the abstract was published in Bulletin of the American Physical Society, Vol.48, April 1998.
Xuesheng Chen, John Collins, B. DiBartolo and D. Weyburne, “Upconversion Luminescenceof Er3+ Doped Yttrium Scandium Gallium Garnet at Different Temperatures,” Journal of Luminescence, Vol.72-74, June 1997, pp.168-170.
Xuesheng Chen, B.DiBartolo and John Collins, “Temperature Dependence of Near Infrared to Visible Upconversion Luminescence of Er3+ in YSGG,” in Ultrafast Dynamics of Quantum System:Physical Processes and Spectroscopy Techniques, Proceedings of a NATO Advanced Study Institute, Erice, Sicily, 15-30 June 1997, published by Plenum Press, New York, 1998.
Xuesheng Chen, David Weyburne and Qing S. Paduano, “Non-Destructive Optical Characterization of InGaAs Epitaxial Layer Composition, Thickness and Optical Quality,” in Ultrafast Dynamics of Quantum System:Physical Processes and Spectroscopy Techniques, Proceedings of a NATO Advanced Study Institute, Erice, Sicily, 15-30 June 1997, published by Plenum Press, New York, 1998.
Qing Paduano, David Weyburne, Xuesheng Chen, “Optical Determination of InxGa1-xAs Composition on InP Using a Fabry-Perot Test Structure,” Proceedings of the 9th International Conference on Indium Phosphide and Related Materials, May 11-15, 1997, Hyannis, MA.
Chia-Yen Li, Vladimir Fuflyigin, Jing Zhao, Xuesheng Chen, Seppo Honkanen and Nasser Peyghambarian, “Er-Doped Fluoride Glass Films by MOCVD for Waveguide Devices,” in Rare-Earth-Doped Devices, Proceedings of SPIE (the International Society for Optical Engineering ), San Jose, California, February 1997, Vol. 2996, 1997, pp68-73.
Xuesheng Chen, J. Collins, B. DiBartolo, Feng Lu and D. Weyburne, “Infrared to Visible Up-conversion in Trivalent Erbium Doped Laser Crystals,”, Bulletin of the American Physical Society, Vol.40, October 1995.
Xuesheng Chen, John Collins and B. Di Bartolo, “Thermal Red and Blue shifts of Nd Ion Spectral Lines in Laser Garnet Crystals,” Journal of Luminescence, Vol.60&61, pp230-232, 1994.
J.M. Collins, X. Chen and B. DiBartolo, “Upconversion and Energy Transfer in Er:YSGG and Er:GGG,” Bulletin of American Physical Society, Vol.39, April 1994.
Xuesheng Chen and B. Di Bartolo, “Temperature Dependence of Linewidths and Lineshifts of Nd3+ Ions in CaY2Mg2Ge3O12 Garnet,” Journal of Applied Physics, Vol. 75, No.3, 1 February 1994, pp1710-1714.
Xuesheng Chen and B. Di Bartolo, “Phonon Effects on Sharp Luminescence Lines of Nd3+ in Gd3Sc2Ga3O12 Garnet (GSGG),”, Journal of Luminescence, Vol.54, pp309-318, 1993.
Xuesheng Chen, John Collins and B. Di Bartolo, “Observation of the Blue Shift with Increasing Temperature of the R1-Z5 Line Position of Nd3+ in Garnet Laser Crystals,” Bulletin of the American Physical Society, Vol. 38, 1993.
Xuesheng Chen and B. Di Bartolo, “Thermal Behavior of Spectral Line Positions and Widths of Nd3+ in GSGG,” in Optical Properties of Excited States in Solids, Proceedings of a NATO Advanced Study Institute held in 16-30 June 16-30, Plenum Press, New York, 1992, p699.
Xuesheng Chen and B. Di Bartolo, “Thermal Behaviors of Sharp Spectral Lines of the Nd3+ in Laser Crystals,” Bulletin of the American Physical Society, Vol. 36, 1991.
Book: Advances in Nonradiative Processes in Solids, Proceedings of a NATO Advanced Study Institute held in Erice, Italy, 15-29 June 1989, ed. B. Di Bartolo and Xuesheng Chen, Plenum Press, New York, 1990.
Fengzhi Xu, Peiwei Zeng and Xuesheng Chen, “Ic-T Dependence of the Pulse-Treated Bridge,” Proceedings of the Joint Sino-Japanese Seminar on Josephson Effect Physics and Applications, October 1983, Beijing, China, p45.
Optical studies on various laser materials and other optical materials.