A5004068265- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Laser-Matter Interactions and Applications
- Spectroscopy and Quantum Chemical Studies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Photochemistry and Electron Transfer Studies
- Photonic Crystal and Fiber Optics
- Photonic and Optical Devices
- Mass Spectrometry Techniques and Applications
- Porphyrin and Phthalocyanine Chemistry
- Atomic and Subatomic Physics Research
- Optical and Acousto-Optic Technologies
- Semiconductor Lasers and Optical Devices
- Advanced Chemical Physics Studies
- nanoparticles nucleation surface interactions
- Advanced Fiber Optic Sensors
- Diamond and Carbon-based Materials Research
- Analytical Chemistry and Sensors
- Laser Design and Applications
- Photorefractive and Nonlinear Optics
- Solid State Laser Technologies
- Thermography and Photoacoustic Techniques
- Photoreceptor and optogenetics research
- Electrochemical Analysis and Applications
- Protein Interaction Studies and Fluorescence Analysis
Stony Brook University
2017-2024
Stony Brook Medicine
2021
Yuncheng University
2018
National Institute of Standards and Technology
2018
Stevens Institute of Technology
2017
Spectroscopy in the molecular fingerprint spectral region (6.7–20 µm) yields critical information on material structure for physical, chemical, and biological sciences. Despite decades of interest effort, this portion electromagnetic spectrum remains challenging to cover with conventional laser technologies. In paper, we present a simple robust method generating super-octave, optical frequency combs through intra-pulse difference generation an orientation-patterned gallium phosphide crystal....
Mid-infrared laser frequency combs are compelling sources for precise and sensitive metrology with applications in molecular spectroscopy spectro-imaging. The infrared atmospheric window between 3-5.5 $\mu$m particular provides vital information regarding composition. Using a robust, fiber-optic source of few-cycle pulses the near-infrared, we experimentally demonstrate ultra-broad bandwidth nonlinear phenomena including harmonic difference generation single pass through periodically poled...
We report on the development of a high-power mid-infrared frequency comb with 100 MHz repetition rate and fs pulse duration. Difference generation is realized between two branches derived from an Er:fiber comb, amplified separately in Yb:fiber amplifiers. Average powers 6.7 W 14.9 are generated 2.9 µm idler 1.6 signal, respectively. With high average power, excellent beam quality, passive carrier-envelope phase stabilization, this light source promising platform for generating broadband...
Salicylideneaniline (SA) is an archetypal system for excited-state intramolecular proton transfer (ESIPT) in non-planar systems. Multiple channels relaxation involving both the keto and enol forms have been proposed after excitation to S1 with near-UV light. Here, we present transient absorption measurements of hot gas-phase SA, jet-cooled SA Ar clusters using cavity-enhanced spectroscopy (CE-TAS). Assignment spectra aided by simulated TAS spectra, computed applying time-dependent complete...
We present an ultrasensitive ultrafast transient absorption spectrometer which allows for all-optical measurements in gas-phase systems. discuss the design of instrument, show first results, and compare to other techniques.
Transient absorption spectroscopy (TAS) is among the most common ultrafast photochemical experiments, but its interpretation remains challenging. In this work, we present an efficient and robust method for simulating TAS signals from first principles. Excited-state stimulated emission (SE) are computed using time-dependent complete active space configuration interaction (TD-CASCI) simulations, leveraging robustness of time-domain simulation to minimize electronic structure failure. We...
We describe the cavity-enhancement of frequency combs over a wide tuning range 450-700 nm (> 7900 cm$^{-1}$), covering nearly entire visible spectrum. Tunable from synchronously-pumped optical parametric oscillator are coupled into 4-mirror, dispersion-managed cavity with finesse 600 to 1400. An intracavity absorption path length enhancement greater than 190 is obtained range, while preserving spectral bandwidths capable supporting sub-200 fs pulse durations. These tunable cavity-enhanced...
We present a scheme for generating super-octave, long-wave infrared combs in the molecular fingerprint region using intra-pulse difference frequency generation an orientation patterned GaP crystal. demonstrate high resolution dual-comb spectroscopy methanol vapor.
We describe a nonlinear Er:doped fiber amplification scheme for producing fiber-delivered, 44 fs pulses with 100 kW peak power at arbitrary (0-60 MHz) repetition rate. Subsequent spectral broadening produces 80 THz of bandwidth.
Transient absorption spectroscopy (TAS) is among the most common ultrafast photochemical experiments, but its interpretation remains challenging. In this work, we present an efficient and robust method for simulating TAS signals from first principles. Excited-state stimulated emission (SE) are computed using time-dependent complete active space configuration interaction (TD-CASCI) simulations, leveraging robustness of time-domain simulation to minimize electronic structure failure. We...
Spectroscopy in the molecular fingerprint spectral region (6.5-20 $μ$m) yields critical information on material structure for physical, chemical and biological sciences. Despite decades of interest effort, this portion electromagnetic spectrum remains challenging to cover with conventional laser technologies. In report, we present a simple robust method generating super-octave, optical frequency combs through intra-pulse difference generation an orientation-patterned gallium phosphide...
Salicylidenaniline (SA) is an archetypal system for excited-state intramolecular proton transfer (ESIPT) in non-planar systems. Multiple channels relaxation involving both the keto and enol forms have been proposed after excitation to S$_1$ with near-UV light. Here we present transient absorption measurements of hot gas-phase SA, jet-cooled SA Ar clusters using cavity-enhanced spectroscopy (CE-TAS). Assignment spectra aided by simulated TAS spectra, computed applying time-dependent complete...
We demonstrate the generation of broadband (6—12 μm) long-wave infrared frequency combs via intra-pulse difference-frequency in orientation-patterned gallium phosphide and use source to perform dual-comb spectroscopy on methanol.
Using an amplified single-branch Er:fiber laser (100 MHz), we generate infrared (3– 12 µm) frequency combs in a combination of lithium niobate and orientation-patterned gallium phosphide. Dual-comb spectroscopy trace gases alcohol vapors is demonstrated.
Ultrafast optical spectroscopy methods, such as transient absorption and 2D spectroscopy, are typically restricted to optically thick samples, solids liquid solutions.We have developed a technique, Cavity-Enhanced Spectroscopy, study dynamics in molecular beam with femtosecond temporal resolution.By coupling frequency combs into cavities, we previously demonstrated ultrafast measurements detection limit of ∆OD = 2 × 10 -10 (10 -9 / √ Hz). In this talk, I will present widely tunable version...
Generation of widely tunable frequency combs in the UV, visible, and infrared is discussed for use cavity-enhanced transient absorption spectroscopy on gas-phase clusters. Progress towards two-dimensional also presented.