The Center for Advanced Photonics Research at Temple University focuses on understanding the photochemistry and photophysics of molecules interacting with ultrafast, ultra-intense laser pulses. Ultrafast means laser pulses that are only a few millionths of a billionth of a second, our shortest pulses approach just 5 femtoseconds in duration. Ultra-intense means laser fields approaching the fields binding electrons within molecules. The combination of these two properties creates environments and interactions that are unique in the universe and thus new phenomena arise. Since 1991 we have been discovering and understanding such new phenomena, an area that we call strong field chemistry.
The current areas of research in the Center for Advanced Photonics Research involve laser vaporization of condensed phase systems, laser filamentation in air, laser generation and processing of nanomaterials in the solution, solid, and gas phases, the control of chemical reactions using shaped laser pulses, the elucidation of laser plasma evolution and investigations and control of the strong field, time-dependent Rabi oscillation. These efforts are leading to new ways to diagnose disease, map cellular components, detect improvised explosive devices, classify tissues and phenotype, classify explosives for forensics analysis, and to synthesize monodispersed nanomaterials.
The Center for Advanced Photonics Research is a multidisciplinary organization that includes eight faculty actively collaborating from disciplines including physical, analytical and inorganic chemistry, and theoretical and experimental physics. Graduate and undergraduate students are drawn from all areas of science to form research teams to address questions including:
Nanomaterials by design:
Can we produce the highest purity of nanomaterials (quantum dots, metallic alloys, nanodiamond) using the nonequilibrium energy deposition of shaped laser pulses?
Can we grow nanodiamond on tissue?
Laser Vaporization Mass Spectrometry:
Can we map the molecular signatures and biomarkers in cells on the submicron level? What is the transfer mechanism of biomolecules, including proteins and viruses, from the solid state into the gas phase?
Can we access top down protein sequencing by charging proteins beyond the supercharging limit?
Can we develop gas phase spectroscopic methods that are sensitive enough to detect trace signatures in air at the part per billion level for detecting improvised explosive devices?
Can we detect gas phase molecular signatures of radioactive materials?
What are the fundamental nonlinearities important for laser filamentation?
Can we calculate the nonlinear properties of N2 and O2 neutrals and ions to enable first principles nonlinear propagation calculations for laser filamentation?
Laser Control of Chemical Reactions:
What are the limits of laser control of chemical reactivity and what are the mechanisms of strong field control?
Will the control of chemical reactivity increase when the molecule is ionized prior to application of the control pulse?
Can we measure the electronic spectra of radical cations?
Time-Dependent Rabi Oscillation:
Can we phase match the broad bandwidth emission from the time-dependent Rabi oscillation to form a new laser source?
What is the evolution of the initial electron dynamics after strong field ionization in air?