Research
Courses
Publications
People
Contact
Research
Optofluidics | Femtosecond Nonlinear Optics | Holography
The Psaltis group works on optical information systems including memories, computers, sensors, and communications. The current research projects are in the following areas.
Optofluidics: Fluids are used to synthesize novel optical systems. The optical properties of fluids can be modified by chemical synthesis relatively easily and the insertion of fluids in the optical path specifies or adapts the functionality of the optical system. One of the approaches we are pursuing is the integration of microfluidic circuits with photonic structures that contain voids into which fluids are injected. Another approach is the use of colloidal solutions o f nanoparticles. Electrical fields or light beams redistribute the nanoparticles and modify the optical properties of the structure. Liquid dyes injected into microfluidic chips provide the optical gain necessary for building a dye laser on a chip. (http://www.optofluidics.caltech.edu/)
Femtosecond nonlinear optics: We are studying nonlinear propagation of femtosecond pulses in fibers and 3-D media. The nonlinearity produces very distinctive diffraction patterns such as self focusing and solitary waves (waves that remain stable as the beam propagates). We developing techniques that utilize these rich nonlinear behaviors for information processing applications. For example we have shown that light propagation in a medium with the appropriate nonlinearity is equivalent to turbid flow in fluid mechanics. This suggests that we might be able to build optical systems to simulate turbulence.
Femtosecond papers
Beam Filamentation
A femtosecond pulse breaks up into filaments after traversing a nonlinear material.
Related video clip Formation of optical filaments
Holography: The group has developed a wide variety of holographic materials, techniques, and applications. The current focus in this area is the use of holograms as wavelength filtering elements and femtosecond holography. Wavelength filters with unique properties can be synthesized using the wavelength selectivity of volume holograms. Recording holograms with femtosecond pulses makes it possible to make short holographic movies of very fast events and replay them in three dimensions.
Holography Papers
Cover of Science, Volume 298, NOV 15, 2002, Article pp. 1359-1363
