William E. Leonhard Professor of Electrical Engineering
Director – Liquid Crystals and Nonlinear Optics Laboratory
216 Electrical Engineering East
The Pennsylvania State University
University Park, PA 16802
Tel: (814) 863-2299; Fax: (814) 865-7065; E-mail: ick1@ psu.edu
B. Sc. (1st Class Honors) Physics, University of Malaya 1971
M.A. Physics, University of Rochester, Rochester, NY 1973
Ph D. Physics, University of Rochester, Rochester, NY 1976
2006 – Present – William E. Leonhard Chair Professor of Electrical Engineering
2000 – 2006 – Distinguished Professor of Electrical Engineering
1987- 2000 – Pennsylvania State University-Professor of Electrical Engineering
9/98 –1/99 – Princeton University EE Department] – [sabbatical]
9/90-12/90 – Princeton University Fellow [sabbatical]- Physics Department
1984-1987 – Pennsylvania State University-Associate Professor of Electrical Engineering
4/’84-7/’84- National Research Council, Ottawa, Canada – Senior Visiting Scientist
1979-1984 – Wayne State University-Assistant/Associate Professor of Physics
1/79-9/79 – University of Toronto-Research Fellow
1978-1979 – University of Michigan – Research Associate [with Emmitt Leith]
1977-1978 – University of Southern California -Research Associate
1976-1977 – Ames Laboratory, U.S. Department of Energy, Iowa-Postdoctoral Fellow
Professional Society Membership:
° Optical Society of America (OSA – Fellow
° UK Institute of Physics – Fellow
° Institute of Electrical and Electronics Engineers (IEEE) – Fellow
° The Electromagnetics Academy – Fellow
Honors and Awards:
° Chair of the United State Advisory Committee /ICO – The National Academies (Sciences and Engineering) 1/2008-12/2010.
° The Electromagnetics Academy – Awarded Fellow (2014)
° Vice President International Commission for Optics (ICO) [2005-2008; 2008-2010]
° Awarded Sir Pao Yu-Kong Chair Professorship (Honorary) by Zhejiang University, China (2014-2018)
° 2003 Sturgeon Memorial Plenary Lecturer, Cambridge University [British Liquid Crystal Society]
° Vice President –Technical Affairs, IEEE –Lasers and Electro-Optics Society (2001 -2004)
° Awarded Distinguished Professorship – Pennsylvania State University (2000-2006)
° UK Institute of Physics (Inst. P) – Awarded Fellow (1999)
° IEEE Lasers and Electro-Optics Society – Elected Fellow (1998)
° Pennsylvania State Engineering Society-Premier Research Award (1995)
° Penn State Research Foundation Invention Incentive Awards (1994, 1995)
° Appointed Laser Specialist by World Bank to evaluate Key Universities in China (1990)
° Pennsylvania State University –Faculty Scholar Medal for Outstanding Achievement in Physical Science and Engineering (1988)
° Optical Society of America – Elected Fellow (1988)
° Pennsylvania State Engineering Society- Outstanding Research Faculty Award (1987)
° Research Corporation Cottrell Research Award (1981)
– National Academy of Science and Academy of Engineering: United States Advisory Committee/Int. Comm. For Optics [Chair (1/2008 – 12/2010); Member (1/2006 -12/2013)]
– Technical Journal Referee: J. Optical Society of America B; Optics Express, Optics Letters; Physical Reviews and Physical Review Letters; Optics Communication; Liquid Crystals; Molecular Crystals Liquid Crystals; Applied Optics; Applied Physics Letters; Journal of Appl. Physics; Nature Photonics.
– Proposal reviewer/panelist for NSF, AFOSR, ARO; Government Scientific Research Agencies of Canada, Italy, Belgium, Poland, Hong Kong, UK, Austria.
– Current Advisory Board Member of two national research centers: (1) The Center for Opto-Electronic Materials and Devices (COMD), Shanghai Jiao-Tung University and (2) State Key Laboratory on Advanced Displays and Optoelectronics Technologies (ADT), Hong Kong University of Science and Technology.
– External Ph. D. Examiner – Trinity College (Physics), Dublin, Ireland (2001); Chalmers University (Physics), Sweden (2002); Cambridge University (Electrical Engineering), UK (2005)
– Editor-in-Chief of “Journal of Nonlinear Optical Physics & Materials,” (1991-Present); Editorial Board member of two international journals: Advance Device Materials [France]; Liquid Crystal Displays [Korea]
– Chairmanship of international technical conferences:-
* IEEE Lasers and Electro-Optics Society
– Chair of IEEE Lasers and Electro-Optics Society Technical Council [11/2001-11/2004]
– Chair, Nonlinear Optics Technical Committee (‘92 -’95, ’99 –‘03)
– Chair, 2001Annual Meeting Nonlinear Optics Subcommittee
– Chair, 1990 Nonlinear Optics: Materials, Phenomena and Devices
– Chair, Nonlinear Optics Technical Committee, 2005
– Conference co-chair, 2007 IEEE-LEOS Topical Meeting on “Organic Photonics Media, Devices and Application,” Portland, Oregon.
* Optical Society of America
– Chair, Steering/Program Committee -Nonlinear Optics ‘92, ‘94, ’96, ’98, ’00, ’03.
– Program co-chair “Int. topical Meeting on Optics of Liquid crystals”, Clearwater, Florida 10/2005.
* SPIE – Society for Photo-Optical Instrumentation Engineer
– Chair, Technical Symposium on Aerospace Sensing-Optical Switches and Electro- Optic Materials ‘89, ’90, ‘92.
– Chair, Liquid Crystals Conference I – XXI (1997-2017) in SPIE Optics and Photonics Annual Symposium.
* European Technical Societies
– Program co-chair, 1st –13th Mediterranean Workshop on Novel Optical Materials and Applications,” Cetraro, Italy (’95 –‘17).
* The Electromagnetics Academy
– “Progress in Electromagnetic Research Symposium” (PIERS)
General Program Co-Chair: Stockholm, Sweden (2013); Guangzhou, China (2014); St. Petersburg, Russia (2017).
Photonic Program co-Chair: Prague (2015); Shanghai (2016); Singapore (2017)
Summary of Technical Publications/Patent
*Author/co-author/editor of 7 books and 14 book chapters.
* Editor of 20 Conference Proceeding volumes [Liquid Crystal Conference I –XX]
* Editor-in-Chief of 25 Volumes-year of Journal [JNOPM 1991-2016].
* H-Index: 45; over 6500 citations in Science Citation Index.
* Authored and co-authored ~ 662 Technical Publications/Conference Presentations [281 Refereed Journals and Proceedings; 381 (~203 invited) Conference Presentations]
* Awarded three U.S. patents:
– US Patent # 5,552,915 “Liquid Crystal Nonlinear Photorefractive Electro-Optical Storage Device Having a Liquid Crystal Film including Dopant species of C60 and C70” [9/3/1996]. Sole inventor.
– US Patent #5,589,101“Liquid Crystal Fiber Array for Optical Limiting of Laser Pulses and for Eye/Sensor Protection” [12/31/1996]. Sole inventor. Invention featured in Innovation to Watch section of Business Week [May 5, ‘97 Issue], Discovery magazine [3/2000] and Photonic Spectra [6/2000], MIT Technology Review [4/2000] and several National Newspapers [New York Times, Philadelphia Inquirer, Houston Chronicles]
– US Patent # 9,140,914 “Apparatus and Method for Stabilizing the Temperature of a Photonic Circuit” [9/22/2015]. List of co-inventors: Joanna Ptasinski, Lin Pang, Iam Choon Khoo, Yeshaiahu Fainman, Sungwoon Kim.
- Author – Liquid Crystals: Physical Properties and Nonlinear Optical Phenomena (Wiley, NY, 1995). A 300-page reference/text book intended for graduate students, optical engineers and research scientists interested in liquid crystal nonlinear optics and basic physics.
- Author – Liquid Crystals 2nd Edition (Wiley, NY 2007). A 400-page reference/text book intended for optical engineers, research scientists and graduate students interested in the physics, electro-optics and nonlinear optics of liquid crystals.
- Co-author – Optics and Nonlinear Optics of Liquid Crystals (World Scientific Publishing Inc., NJ, May 1993). A 500 page reference book that provides a comprehensive treatment of the fundamentals of optical, electro-optical and nonlinear-optical properties of liquid crystals, devices and nonlinear optics.
- Co-editor – Nonlinear Optics and Optical Physics (World Scientific, Singapore, 1993). A 400-page reference book, with 16 authors, intended for advanced research scientists.
- Co-editor – Physics of Liquid Crystalline Materials (Gordon & Breach, NY, 1991). A 600-page reference book, with 26 authors, intended for advanced researchers.
- Co-author – Principles of Optical Engineering (Wiley, NY, 1990). A 260 –page junior/senior year Electrical Engineering textbook.
- Co-editor – Novel Optical Materials and Applications (Wiley, NY, 1996). A 320-page reference book for research level optical scientist/engineers.
Journals and Proceedings
- Editor-in-Chief – J. Nonlinear Optical Physics and Materials, Vol. 1- Vol. 26 [1992 – present]
- Editor – Liquid Crystals I -XX [1997- 2016] – 20 Proceedings Volumes of Liquid Crystals Conference in the Annual SPIE Optics and Photonics Symposium.
- Theory of optically induced molecular reorientations and quantitative experiments on wave mixing and the self-focusing of light. I. C. Khoo, Phys. Rev., A25, 1637 (1982).
- Optical bistability in a nematic liquid crystal film inside a Fabry Perot cavity. I. C. Khoo, R. Normandin and V.C.Y. So, J. Appl. Phys., 53, 7599 (1982).
- Re-examination of the theory and experimental results of optically induced molecular reorientation and nonlinear diffractions in nematic liquid crystals: spatial frequency and temperature dependence. I. C. Khoo, Phys. Rev., A27, 2747 (1983).
- Theory and experiment on optical bistability in a Fabry-Perot interferometer with an intracavity nematic liquid-crystal film. I. C. Khoo, J. Y. Hou, R. Normandin and V.C.Y. So, Phys. Rev., A27, 3251 (1983).
- Nanosecond laser-induced transient and erasable permanent grating diffractions and ultrasonic waves in a smectic film. I. C. Khoo and R. Normandin, J. Appl. Phys., 55, pp.1416-1418, (1984).
- Nanosecond degenerate optical wave mixing and ultrasonic wave generation in the nematic phase of liquid crystals. I. C. Khoo and R. Normandin, Opt. Letts., 9, 285-287 (1984).
- Observation of intensity-dependent guided waves, H. Vach, C. T. Seaton, G. I. Stegeman and I. C. Khoo, Opt. Letts., 9, 238 (1984).
- Theory and experiment on optical transverse intensity bistability in the transmission through nonlinear thin (nematic liquid crystal) film. I. C. Khoo, P. Y. Yan, T. H. Liu, S. Shepard and J. Y. Hou, Phys. Rev., A29, 2756 (1984).
- The mechanism and dynamics of transient thermal grating diffraction in nematic liquid crystal films. I. C. Khoo and R. Normandin, IEEE J. Quant. Electronics, QE-21, 329 (1985).
- Nonlinear Fabry Perot action and optical bistability of a dielectric cladded thin film near the total internal reflection state, I. C. Khoo and J. Y. Hou, J. Opt. Soc., Am. B2, 761 (1985).
- Liquid crystals–nonlinear optical properties and processes. I. C. Khoo and Y. R. Shen, (invited paper) Optical Engineering, 24, 579 (1985).
- Nonlocal transverse dependence of molecular reorientation induced in a nematic liquid crystal by a Gaussian laser beam. I. C. Khoo, T. H. Liu and R. Normandin, Mol. Cryst. Liq. Cryst. 131, p. 315 (1985).
- Infrared to visible image conversion capability of nematic liquid crystal film. I. C. Khoo and R. Normandin, Appl. Phys. Letts. 47, 350 (1985).
- Theory and experiment on optically induced nematics axis reorientation and nonlinear effects in the nanosecond regime. I. C. Khoo, R. R. Michael and P. Y. Yan, IEEE J. Quant. Electronics, QE23, 267 (1987).
- Nonlocal transverse dependence of optically induced director axis reorientation of a nematic liquid crystal film–theory and experiment. I. C. Khoo, P. Y. Yan and T. H. Liu, J. Opt. Soc. Am., B, Vol. 4, p. 115 (1987).
- Transverse self-phase modulation and bistability in the transmission of a laser beam through a nonlinear thin film. I. C. Khoo, J. Y. Hou, T. H. Liu, P. Y. Yan, R. R. Michael and G. M. Finn, J. Opt. Soc. Am., B4, 886 (1987).
- Probe beam amplification via two- and four-wave mixings in a nematic liquid crystal film. I. C. Khoo and T. H. Liu, IEEE J. Quant. Elect., JQE 23, 171 (1987).
- Low power (10.6μm) laser beam amplification via thermal grating mediated degenerate four wave mixings in a nematic liquid crystal film. I. C. Khoo, P. Y. Yan, G. M. Finn, T. H. Liu and R. R. Michael, J. Opt. Soc. Am., B5, 202 (1988).
- Stationary and moving thermal grating mediated infrared laser wave mixing and amplification in nematic liquid crystal films. P. Y. Yan and I. C. Khoo, IEEE J. Quant. Elect., JQE25, 520 (1989).
- Theory and experiments on multiwave mixing mediated probe beam amplification. I. C. Khoo and T. H. Liu, Phys. Rev., A39, 4036 (1989).
- Optical switching by a dielectric cladded nematic film. I. C. Khoo, et al., IEEE J. Quant. Elect., JQE25, 1755 (1989).
- Nonlinear liquid crystal fiber-fiber coupler for switching and gating operation. I. C. Khoo and R. Normandin, J. Appl. Phys., 65, 2566 (1989).
- Transient multiwave mixing in a nonlinear medium. I. C. Khoo and P. Zhou, Phys. Rev., A41, 1544 (1990).
- A quantitative analysis of picosecond transient multiwave mixings mediated beam amplification effect in silicon. I. C. Khoo, P. Zhou, R. G. Lindquist and P. LoPresti, Phys. Rev., A41, 408 (1990).
- The infrared optical nonlinearities of nematic liquid crystals and novel two-wave mixing processes. I. C. Khoo, J. Mod. Optics, Vol. 37, 1801 (1990).
- Optical amplification and polarization switching in a birefringent nonlinear optical medium: An analysis. I. C. Khoo, Phys. Rev. Lett. 64, 2273 (1990).
- Dynamics of picosecond laser induced density, temperature and flow-reorientation effects in the mesophases of liquid crystals. I. C. Khoo, R. G. Lindquist, R. R. Michael, R. J. Mansfield and P. Lopresti, J. Appl. Phys., 69, 3853 (1991).
- Laser induced thermal, orientational and density nonlinear optical effects in nematic liquid crystal. I. C. Khoo, Phys. Rev. A, 42, 1001 (July 1990).
- Theory and experiments on stationary and nearly degenerate optical wave mixing and ring-laser oscillation in a Kerr-like medium: Stationary regime. I. C. Khoo and Wei Wang, J. Opt. Soc. of Am., B8, 1433 (1991).
- Effects of diffractions and self-phase modulations on phase conjugation self-oscillation in Kerr media. I. C. Khoo and W. Wang, J. Quantum Electronics, JQE27, 1310 (1991).
- Coherent beam amplification and polarization switching in a birefringent medium-photorefractive crystals. I. C. Khoo, Yu Liang, and Hong Li, IEEE J. Quantum Electronics, JQE 28, pp. 1816-1824 (1992).
- Nonlinear interface tunneling phase shift. I. C. Khoo and P. Zhou, Optics Letts., 17, pp. 1325-1327 (1992).
- Dynamics of transient probe beam amplification via coherent multiwave mixing in a local nonlinear medium-nematic liquid crystal. I. C. Khoo, Hong Li, and Yu Liang, IEEE J. Quant. Electronics, 29, 12 (1993).
- Optically induced extraordinarily large negative orientational nonlinearity in dye-doped-liquid crystal. I. C. Khoo, H. Li, and Y. Liang, IEEE J. Quant. Electron, JQE29, pp. 1444-1447 (1993).
- Self-starting optical phase conjugation in dyed nematic liquid crystals with a stimulated thermal-scattering effect. I. C. Khoo, H. Li and Y. Liang, Opt. Letts. 18, 1490 (1993).
- Observation of optical limiting and backscattering of nanosecond laser pulses in liquid crystal fibers. I. C. Khoo, H. Li and Y. Liang, Optics Letts., 19, 530 (1994).
- Transient laser induced orthogonal director axis reorientation in dye-doped liquid crystal. Hong Li, Yu Liang and I. C. Khoo, Mol. Cryst. Liq. Cryst., 251, 85 (1994).
- Observation of orientational photorefractive effects in nematic liquid crystals. I. C. Khoo, H. Li, and Y. Liang, Optics Letts, 19, 1723 (1994).
- Nonlinear optical propagation and self-limiting effect in liquid crystalline fiber. I. C. Khoo and H. Li, Appl. Phys. B, 59, p. 573 (1994).
- Self-starting phase conjugation with cross-polarization stimulated orientational scattering in liquid crystal. I.C. Khoo and Yu Liang, Optics Letters, 20, 130 (1995).
- Holographic grating formation in dye- and fullerene C60-doped nematic liquid crystal film. I. C. Khoo, Optics Letters, 20, 2137 (1996).
- All Optical switching of infrared optical radiation using isotropic liquid crystals. P. G. LoPresti, P. Zhou, R. G. Lindquist and I. C. Khoo, IEEE J. Quantum Electronics, JQE 31, pp. 723 (1995).
- Optical-dc-field induced space charge fields and photorefractive-like holographic grating formation in nematic liquid crystals. I.C.Khoo. Mol. Cryst. Liq. Cryst, 282, pp.53-66 (1996).
- Orientational photorefractive effects in nematic liquid crystal film. I. C. Khoo, IEEE J. Quantum Electronics JQE 32, pp. 525-534 (1996).
- Nonlinear Liquid Crystal Fiber Structures for Passive Optical Limiting of Short Laser Pulses. I. C. Khoo, M. V. Wood, M. Lee and Brett D. Guenther. Optics Letters 21, 1625 -1627 (1996).
- Coherent beam amplification with photorefractive liquid crystal. I. C. Khoo, Brett D. Guenther, M. V. Wood, P. Chen and Min-Yi Shih, Opt. Lett. 22,1229 (1997).
- Nonlinear- absorption and optical limiting of laser pulses in a liquid-cored fiber array . I. C. Khoo, M. V. Wood, B. D.Guenther, Min-Yi Shih and P. H. Chen. J. Opt. Soc. Am. B15, pp. 1533-1540, 1998.
- C. Khoo, S. Slussarenko, B. D. Guenther and W. V. Wood, “Optically Induced Space Charge Fields, DC Voltage, and Extraordinarily Large Nonlinearity in Dye-doped Nematic Liquid Crystals,” Opt. Letts 23, pp 253 – 255 (1998).
- C. Khoo, M. V. Wood, B. D. Guenther, Min-Yi Shih, P. H. Chen, Zhaogen Chen and Xumu Zhang, “Liquid Crystal Film and Nonlinear Optical Liquid Cored Fiber Array for ps-cw Frequency Agile Laser Optical Limiting Application”. Optics Express, Vol. 2, no. 12.pp 471-82, (1998)
- C. Khoo, M. V. Wood, M. Y. Shih and P. H. Chen, “Extremely Nonlinear Photosensitive Liquid Crystals for Image Sensing and Sensor Protection,” Optics Express, Vol. 4, no. 11, pp 431-442 (1999)
- Y. Shih, I. C. Khoo, A. Shishido, M. V. Wood, P. H. Chen, “All-Optical Image Processing with A Supra Nonlinear Dye-Doped Liquid Crystal Film”, Opt. Letts. 25, 978-980 (2000).
- Peccianti, A. De Rossi and G. Assanto, A. De Luca and C. P. Umeton and I. C. Khoo, “Electrically assisted self-confinement and waveguiding in planar nematic liquid crystal cells, ” Appl. Phys. Letts. 77, pp 7-9 (2000).
- C. Khoo and Y. Liang, “Stimulated Orientational and Thermal Scatterings and Self-Starting Optical Phase Conjugation with Nematic Liquid Crystals,” Phys. Rev. E62, pp 6722 –6733 (2000).
- C. Khoo, P. H. Chen, M. Y. Shih, A. Shishido, S. Slussarenko, “Supra Optical Nonlinearities of Methyl Red- and Azobenzene Liquid Crystal- doped Nematic Liquid Crystals,” Mol. Cryst. Liq. Cryst. 358, 1-13 
- C. Khoo, M. Y. Shih, A. Shishido, P.H. Chen and M. V. Wood , “Liquid Crystal Photorefractivity – Towards Supra-Optical Nonlinearity,” Opt. Mate. 18, 85-90 (2001).
- C. Khoo, M. Y. Shih and A. Shishido, “Supra Optical Nonlinearities of Photosensitive Nematic Liquid Crystals,” Mole. Cryst. Liquid. Cryst. 364, 141-149, (2001).
- Y. Shih, A. Shishido and I. C. Khoo, “All-optical image processing by means of photosensitive nonlinear liquid crystal film: edge enhancement and image addition/ subtraction,” Opt. Letts. 26, pp 1140-1142 (2001).
- C. Khoo, A. Diaz, M. V. Wood and P. H. Chen , “Passive optical limiting of picosecond – nanosecond lasers using highly nonlinear organic liquid cored fiber array,” IEEE J. Selected Topics in Quantum Electronics, Vol. 7, no. 5, pp. 760-768 (2001).
- Ivan B. Diviliansky, Atsushi Shishido, I. C. Khoo, Theresa S. Mayer, David Pena, Suzushi Nishimura, and Thomas E. Mallouk, “Fabrication of two-dimensional photonic crystals using interference lithography and electrodeposition of CdSe,” Appl. Phys. Letts. 79, 3392-3394 (2001).
- Assanto, M. Peccianti, C. Umeton, A. De Luca and I. C. Khoo, “Coherent and incoherent spatial solitons in bulk nematic liquid crystals,” Mol. Cryst. Liq. Cryst. 375, pp 617-629 (2002).
- Malgosia Kaczmarek, Min-Yi Shih, Roger S. Cidney and I. C. Khoo, “Electrically tunable, optically induced dynamic and permanent gratings in dye-doped liquid crystals”, IEEE J. Quantum Electronics 38, pp 451-457 (2002)
- C. Khoo and J. Ding, “All-optical cw laser polarization conversion at 1.55 micron by two beam coupling in nematic liquid crystal film,” Appl. Phys. Letts. 81, pp. 2496-2498 (2002).
- C. Khoo, J. Ding, Y. Zhang, K. Chen and A. Diaz, “Supra-Nonlinear Photorefractive Response of Single-wall Carbon Nanotube- and C60-Doped Nematic Liquid Crysta1s,” Appl. Phys. Letts. 82, pp. 3587-3589 (2003).
- C. Khoo and A. Diaz, “Nonlinear dynamics in laser polarization conversion by stimulated scattering in nematic liquid crystal films,” Phys. Rev. E68 pp 042701-1 to -4 
- C. Khoo, K. Chen and A. Diaz, “All-Optical Neural-net like Image Processing with Photosensitive Nonlinear Nematic Film,” Optics Letts. 28, pp 2372-2374 .
- C. Khoo, Andres Diaz and J. Ding, “Nonlinear-absorbing Fiber Array for Large Dynamic Range Optical Limiting Application against Intense Short Laser Pulses, J. Opt. Soc. Am B21, pp. 1234-1240 .
- Ye, J. Ding, D. Jeong, I. Khoo and Q. Zhang, “Finite-size effect on one-dimensional coupled resonator optical waveguides” Phys. Rev. E 69, 056604 (2004).
- Malgosia Kaczmarek, Andrey Dyaduysha, Sergei Slussarenko and I.C. Khoo, “The role of surface charge field in two-beam coupling in liquid crystal cells photoconductingpolymer layers,” J. Appl. Phys. 96, pp. 2616-2623 .
- Iam Choon Khoo, Jianwu Ding, and Andres Diaz, “Dynamics of Cross-polarization Stimulated Orientation Scattering in Nematic Liquid Crystal Film,” J. Opt. Soc. Am. B22, pp. 844-851 
- C. Khoo, Yana Zhang Williams, B. Lewis and T. Mallouk, “Photorefractive CdSe and gold nanowire-doped liquid crystals and polymer-dispersed-liquid-crystal photonic crystals,” Mol. Cryst. Liq. Cryst. 446: 233-244 (2005).
- C. Khoo, Kan Chen and Y. Zhang Williams, “Orientational Photorefractive Effect in undoped and CdSe Nano-Rods doped Nematic Liquid Crystal – Bulk and Interface Contributions,” IEEE J. Selcted Topics in Quantum Electronics JSTQE 12 (3), pp. 443-450 .
- Graugnard, J. S. King, S. Jain, C. J. Summers, Y. Zhang-Williams and I. C. Khoo, “Electric field tuning of the Bragg peak in large-pore TiO2 inverse shell opals,” Phys. Rev. B72, 233105 (2005).
- C. Khoo, Yana Williams, Andres Diaz, Kan Chen, J. Bossard, D. Werner, E. Graugnard and C. J. Summers, “Liquid-Crystals for optical filters, switches and tunable negative index material development,” Molecular Crystal Liquid Crystal 453, pp.309-319 (2006).
- C. Khoo, D. H. Werner, X. Liang, A. Diaz and B. Weiner, “Nano-sphere dispersed liquid crystals for tunable negative-zero-positive index of refraction in the optical and Terahertz regimes,” Optics Letts. 31, 2592 (2006).
- H. Werner, D-H Kwon, I. C. Khoo, A. K. Kildeshev and V. M. Shalaev, “Liquid crystalclad near-infrared metamaterials with tunable negative-zero-positive refractive indices,” Optics Express Vol. 15, No. 6, pp 3342-3347, 2007.
- C. Khoo, Jae-Hong Park and Justin Liou, “All-optical Switching of Continuous Wave Microseconds Lasers with a Dye-doped Nematic Liquid Crystal,” Appl. Phys. Letts. 90, 151107 (2007).
- Shoichi Kubo, Andres Diaz, Yan Tang, Theresa S. Mayer, I. C. Khoo and Thomas E. Mallouk, “Tunability of the refractive index of gold nanoparticle dispersions,” NANO Letts.7, pp. 3418-3423, (2007)
- Wang, D. H. Kwon, D. H. Werner, I. C. Khoo, A. Kildishev and V. M. Shalaev, ‘Tunable optical negative-index metamaterials employing anisotropic liquid crystals,” Appl. Phys. Lett. 91, 143122 (2007).
- C. Khoo, A. Diaz, S. Kubo, J. Liou, Mike Stinger, T. Mallouk and J. H. Park, “Nano-dispersed Organic Liquid and Liquid Crystals for All-Time-Scales Optical Switching and Tunable Negative- and Zero- Index Materials,” Molecular Crystals Liquid Crystals 485:1, pp. 934-944 (2008).
- Bossard, J. A., Liang, X., Li, L., Werner, D. H., Weiner, B., Cristman, P. F., Diaz, A., & Khoo, I. C. (2008), “Tunable Frequency Selective Surfaces and Negative-Zero-Positive Index Metamaterials Based on Liquid Crystals,” IEEE Transactions on Antennas and Propagation, 56, pp. 1308 – 1320 (2008).
- C. Khoo, “Nonlinear Organic Liquid Cored Fiber Array for All- Optical Switching and Sensor Protection against Short Pulsed Lasers,” IEEE J. Selected Topics in Quantum Electronics JSTQE 14, no. 3, pp 946 – 951 (2008)
- C. Khoo, J. H. Park, J. D. Liou, “Theory and experimental studies of all-optical transmission switching in a twist-alignment dye-doped nematic liquid crystal,” J. Opt. Soc. Am. B25, pp. 1931-1937 (2008)
- C. Khoo, “Nonlinear Optics of Liquid Crystalline Materials,” Physics Report 471, pp. 221-267 .
- Shumin Xiao, Uday K. Chettiar, Alexander V. Kildishev, Vladimir Drachev, I. C. Khoo and Vladimir M. Shalaev, “Tunable Magnetic Response of Metamaterials,” Appl. Phys. Lett.Vol. 95 Issue: 3 Article Number: 033115 (2009).
- C. Khoo, S. Webster, S. Kubo, W. J. Youngblood, J. Liou, A. Diaz, T. E. Mallouk, P. Lin, D. Peceli, L. A. Padilha, D. J. Hagan, and E. W. Van Stryland, “Synthesis and characterization of the multi-photon absorption and excited-state properties of 4-propyl 4′-butyl diphenyl acetylene,” J. Mater. Chem. 19, 7525-7531 (2009)
- Pawlik, M. Jarema, W. Walasik, A. C. Mitus and I. C. Khoo, ‘Field induced inhomogeneous index distribution of a nano-dispersed nematic liquid crystal near the Freedericksz transition:Monte carlo studies,” J. Opt. soc. Am. B 27, no. 3 [March 2010]
- N. Christodoulides, I. C. Khoo, G. J. Salamo, G. I. Stegeman, and E. W. Van Stryland, “Nonlinear refraction and absorption: mechanisms and magnitudes,” Adv. Opt. Photon. 2, 60-200 (2010)
- Yan Jun Liu, Qingzhen Hao, Joseph S. T. Smalley, Justin Liou, Iam Choon Khoo, and Tony Jun Huang, “A Frequency-Addressed Plasmonic Switch Based on Dual-Frequency Liquid Crystal,” Appl. Phys. Letts. 97, issue 9, article #: 091101 (2010)
- Antonio d’Alessandro, Rita Asquini, Marco Trotta, Giovanni Gilardi, Romeo Beccherelli, and Iam Choon Khoo, “All-optical intensity modulation of near infrared light in a liquid crystal channel waveguide,” Appl. Phys. Letts. 97, issue 9, article #: 093302 (2010)
- C. Khoo, J. Liou and M. V. Stinger, “Microseconds-Nanoseconds All-Optical Switching of Visible-Near Infrared (0.5 m-1.55 m) Lasers with Dye-Doped Nematic Liquid Crystals ,” Mole. Cryst. Liq. Cryst. 527, pp. 109-118 (2010).
- Diaz and I. C. Khoo, “Liquid crystalline nano-structured optical metamaterials,” in Comprehensive Nanoscience and Technology, Vol. 3, pages 225-261 eds. David Andrews, Gregory Scholes and Gary Wiederrecht [Elseier, 2011]
- C. Khoo and A. Diaz, “Multiple-time-scales dynamical studies of nonlinear transmission of pulsed lasers in a multi-photon absorbing organic material,” J. Opt. Soc. Am – B28 Issue: 7 Pages: 1702-1710 (2011)
- Tony J. Huang, Y. J. Liu, B. Yue, J. Liou and I. C. Khoo, “All-Optical Modulation of Localized Surface Plasmon Coupling in a Hybrid System Composed of Photo-Switchable Gratings and Au Nanodisk Arrays,” Journal of Physical Chemistry 115 Issue: 15 Pages: 7717-7722 (2011)
- C. Khoo, J. Liou, M. V. Stinger and S. Zhao, “Ultrafast All-Optical Switching with Transparent and Absorptive Nematic Liquid Crystals-Implications in Tunable Metamaterials,” Mol. Cryst. Liq. Cryst. 543 Pages: 151-159 (2011)
- Li Jia, Ma Yi; Gu Ying, Q. Gong and I. C. Khoo , “Large spectral tunability of narrow geometric resonances of periodic arrays of metallic nanoparticles in a nematic liquid crystal,” Appl. Phys. Letts., 98 Issue: 21 Article Number: 213101 (2011)
- Zhang Bingxin; Zhao Yanhui; Hao Qingzhen, I. C. Khoo, “Polarization-independent dual-band infrared perfect absorber based on a metal-dielectric-metal elliptical nanodisk array,” Opt. Express 19 Pages: 15221-15228 (2011)
- Smalley Joseph S. T.; Zhao Yanhui; Nawaz Ahmad Ahsan; I. C. Khoo; Tony Huang, “High contrast modulation of plasmonic signals using nanoscale dual-frequency liquid crystals,” Opt. Express 19, Pages: 15265-15274 (2011)
- Hao Qingzhen; Zhao Yanhui; Juluri Bala Krishna, I. C. Khoo and Tony Huang, “Frequency-addressed tunable transmission in optically thin metallic nanohole arrays with dual-frequency liquid crystals, J. Appl. Phys. Volume: 109 Issue: 8 Article Number: 084340 (2011).
- C. Khoo, “Extreme nonlinear optics of nematic liquid crystals,” J. Opt. Soc. Am. B28, pp. A45-A55 (2011). Invited paper in Focus Issue dedicated to 50th Anniversary of Nonlinear Optics. G. Pawlik, K. Tarnowski, W. Walasik, A.C. Mitus and I.C. Khoo, “Infrared cylindrical cloak in nanosphere dispersed liquid crystal metamaterial ,” Optics Letters 37, pp. 1847-1849 (2012)
- Yanhui et al and I. C. Khoo, “Light-driven tunable dual band absorber with liquid-crystal-plasmonic asymmetric nanodisk array,” Appl. Phys.Letts. Article # 053119 (2012)
- C. Khoo and T. H. Lin, “Nonlinear optical grating diffraction in dye-doped blue-phase liquid crystals,” Opt. Lett. 37, 3225-3227 (2012)
- Chun-Wei Chen, Hung-Chang Jau, Chun-Ta Wang, Chun-Hong Lee, I. C. Khoo and Tsung-Hsien Lin, “Random lasing in blue phase liquid crystals,” Optics Express, Vol. 20, No. 21 (2012)
- Piccardi, A. Alberucci, O. Buchnev, M. Kaczmarek, I. C. Khoo, G. Assanto, “Frequency-controlled deflection of spatial solitons in nematic liquid crystals,” Appl. Phys. Letts. 101 Issue: 8 Article Number: 081112 (2012)
- Rui Luo, Ying Gu, Xiankuo Li, Luojia Wang, Iam-Choon Khoo, and Qihuang Gong, “Mode recombination and alternation of surface plasmons in anisotropic mediums,” Appl. Phys. Letts. 102, 011117 (2013)
- Iam Choon Khoo, Kuan Lung Hong, Shuo Zhao, Ding Ma, and Tsung-Hsien Lin “Blue-phase liquid crystal cored optical fiber array with photonic bandgaps and nonlinear transmission properties,” Optics Express Vol. 21 Issue 4, pp.4319-4327 (2013)
- W. Chen, H. C. Jau, C. H. Lee, C. C. Li, C. T. Hou, C. W. Wu, T. H. Lin and I. C. Khoo, “Temperature dependence of refractive index in blue phase liquid crystals,” Optical Materials Express 3 Issue: 5 Pages: 527-532 
- Joanna Ptasinski, Sung W. Kim, Lin Pang, Iam-Choon Khoo, and Yeshaiahu Fainman, “Optical tuning of silicon photonic structures with nematic liquid crystal claddings,” Optics Letters Vol. 38, Iss. 12, pp. 2008–2010 (2013).
- Liyan Song, Shenhe Fu, Yikun Liu, Jianying Zhou, Vladimir G. Chigrinov, and Iam Choon Khoo, “Direct femtosecond pulse compression with miniature-sized Bragg cholesteric liquid crystal,” Optics Letters 38, pp 5040 – 5042 (2013).
- Pawlik, G. Pawlik, W. Walasik, K. Tarnowski, A. C. Mitus, I. C. Khoo, “Liquid crystal hyperbolic metamaterial for wide-angle negative-positive refraction and reflection,” Optics Letters, Vol. 39, Issue 7, pp. 1744-1747 (2014)
- Joanna Ptasinski, Iam-Choon Khoo and Yeshaiahu Fainman, “Passive Temperature Stabilization of Silicon Photonic Devices Using Liquid Crystals,” Materials, 7(3), pages 2229-2241(2014)
- C. Khoo, “Nonlinear Optics, Active Plasmonic and Tunable Metamaterials with Liquid Crystals,” Progress in Quantum Electronics, Volume 38, Issue 2, Pages 77–117 (2014)
- C. Khoo and S. Zhao, “Multiple Time Scales Optical Nonlinearities of Liquid Crystals for Optical-Terahertz-Microwave Applications,” Progress in Electromagnetic Research PIER, Vol. 147, page 37-56, 2014
- C. Khoo, C. W. Chen, K. L. Hong, and T. H. Lin, and S. Zhao “Nonlinear Optics of Nematic and Blue Phase Liquid Crystals,” Molecular Crystals Liquid Crystals, 594:1, 31-41, 
- Joanna Ptasinski, Iam-Choon Khoo, and Yeshaiahu Fainman, “Enhanced optical tuning of modified-geometry resonators clad in blue phase liquid crystals,” Optics Letts. Volume: 39 Pages: 5435-5438(2014)
- C. Khoo, “Dc-field assisted grating formation and nonlinear diffraction in Methyl-red dye-doped blue-phase liquid crystals,” Opt. Lett. 40, pp. 60-63 (2015)
- Chun-Wei Chen, Tsung-Hsien Lin and I. C. Khoo, “Dynamical studies of the mechanisms for optical nonlinearities of methyl-red dye doped blue phase liquid crystals,” Optics Express 23 pages 21650-21656 (2015)
- Nan Wang, Julian S. Evans1, Ju Mei, Jianhao Zhang, Iam-Choon Khoo, and Sailing He, “Lasing Properties of a Dye-doped Cholesteric Liquid Crystal Using an Aggregation-induced-emission Material,” Optics Express 23, pp. 33938-33946 (2015).
- C. Khoo, Shuo Zhao, Tsung-Jui Ho and Chun-Wei Chen, “Maxwell Stress induced flow- deformation and optical nonlinearities in liquid crystals,” Progress in Electromagnetic Research [Invited paper for commemorative issue on 150 years of Maxwell Equations] Vol. 154, 51-63, 2015.
- C. Khoo, Chun-Wei Chen, and Tsung-Jui Ho, “Observation of photorefractive effects in Blue-phase liquid crystal containing Fullerene-C60,” Opt. Letts. Volume: 41Issue: 1 Pages: 123-126 (2016).
- Yikun Liu, You Wu, Chun-Wei Chen, Jianying Zhou, Tsung-Hsien Lin, and Iam Choon Khoo, “Ultrafast pulse compression, stretching-and-recompression using cholesteric liquid crystals,” Optics Express, Vol. 24, Issue 10, pp. 10458-10465 (2016).
- Iam Choon Khoo, Chun-Wei Chen & Tsung-Jui Ho, “High efficiency holographic Bragg grating with optically prolonged memory,” Sci. Rep. 6, 36148; doi: 10.1038/srep36148 (2016).
- Hao, He; Ren, Juanjuan; Chen, Hongyi; Khoo, Iam Choon; Gu, Ying; Gong, Qihuang, “Tunable enhanced spontaneous emission in plasmonic waveguide cladded with liquid crystal and low-index metamaterial,” Optics Express 25(4) 3433-3444(2017).