Atomic, Molecular and Optical Physics Labs

Experimental Astrochemistry & Astrobiology. Investigating the chemical changes induced in low temperature astrochemical ices by electrons, ions (single and multiple charged),dust impacts and shockwaves. Infrared (IR) and Vacuum Ultraviolet (VUV) spectroscopy of astrochemical ice analogs.

Simulator for Astromolecules at Low Temperature (SALT) enables us to recreate the cold dust and icy mantle conditions in the interstellar medium.

High Intensity Shock Tube for Astrochemistry (HISTA) enables us to recreate the shock environment experienced in the interstellar medium and the impact induced shock in the solar system objects. 

Simulator for Astro-molecules at Low Temperature (SALT)

High Intensity Shock Tube for Astrochemistry (HISTA)

Discovering a new class of Astrochemical ices that behave very differently with respect to their phase transition.

Synthesized Graphene and quantum dot in Astrochemical Ices

Created Complex structures by Shock Processing of nucleobases

Only Lab in India that is pursuing Astrochemistry from 8 K to 16k K.

This Laboratory is a 10,000 class cleanroom (ISO 7)  dedicated to investigate  the fundamental processes governing the interaction of intense laser fields with atoms, molecules and condensed matter systems on femtosecond and attosecond time scales. The laboratory is equipped with state-of-the-art ultrafast laser systems.  At the heart of the laboratory is a high-power femtosecond laser system capable of delivering ultrashort pulses with durations of femtoseconds. These pulses serve as versatile tools for initiating and probing ultrafast phenomena, allowing the observation of transient processes that occur on timescales comparable to electronic motion in matter.The laboratory houses multiple advanced experimental platforms, including Velocity Map Imaging (VMI) spectrometers, COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) systems, and High Harmonic Generation (HHG) based Extreme Ultraviolet (XUV) sources. These instruments provide complementary capabilities for studying laser-matter interactions with high temporal, spatial, and momentum resolution.

Lab’s research activities span a broad range of topics, including strong-field ionization, molecular dissociation dynamics, ultrafast spectroscopy, attosecond science, photoelectron spectroscopy, high harmonic generation. By integrating cutting-edge laser technology with sophisticated spectroscopic and imaging techniques, this Laboratory serves as a platform for exploring the fastest processes in nature and training researchers in the rapidly evolving fields of ultrafast and attosecond science. We study these ultrafast dynamical processes with a view to control them during reactions, leading to formation of new molecules.

1. Laser facility and optical system :

●       Femtosecond laser:  800nm, 25fs, 10mJ @ 1KHz and 3mJ @ 5KHz.

●       Femtosecond laser:  1030nm, 190fs, 2mJ @ 10KHz and 200 uJ @ 100KHz

●       Nd- YAG nanosecond laser

●       Spectral Phase Interferometry for Direct Electric-field Reconstruction(SPIDER) for femtosecond pulse characterization.

●       Optical spectrometers ( Avanets, ocean optics, Andor)

2. In- house developed  instruments:

●      Velocity Map Imaging Spectrometer (VMI): The Velocity Map Imaging spectrometers enable detailed measurements of photoelectron and photoion angular and kinetic energy distributions, providing insight into ionization dynamics, molecular fragmentation, strong-field interactions, and ultrafast photochemical processes.

           Figure : In house developed VMI Spectrometer

●     Cold Target Recoil Ion Momentum Spectrometer ( ColTRIMS ): The ColTRIMS apparatus allows coincidence detection of charged particles and reconstruction of their full three-dimensional momentum vectors, facilitating kinematically complete studies of atomic and molecular break-up dynamics.

         
Figure: Inhouse developed Coltrims setup

●     High Harmonic Generation (HHG) setup:  The laboratory's HHG-based XUV sources generate coherent ultrashort radiation in the extreme ultraviolet spectral region, enabling pump-probe experiments with femtosecond and potentially attosecond temporal resolution.

                            Figure : In house developed HHG setup

●     XUV -IR setup:  XUV–IR pump–probe setup  uses ultrashort Extreme Ultraviolet (XUV) and infrared (IR) laser pulses to investigate ultrafast dynamics in atoms and molecules. The XUV pulse initiates or probes a process, while the delayed IR pulse tracks its evolution with femtosecond to attosecond time resolution.
 

                    Figure : In house developed XUV-IR setup

These sources are employed to investigate electron dynamics, charge migration, ultrafast relaxation processes, and strong-field phenomena in atoms and molecules.

 

1.      Study of molecular alignment using femtosecond laser pulses.

2.     Cold Target Recoil Ion Momentum Spectroscopy: Design and Simulation.

3.     Strong-field ionization of polyatomic molecules: ultrafast H atom migration and bond formation in the photodissociation of CH 3 OH.  

DOI: 10.1039/D0FD00129E  

4.     Improving the Signal Strength and Detection Limits of Laser-Induced Breakdown Spectroscopy.

DOI: https://doi.org/10.1007/978-981-33-6084-6_12

5.     Modern experimental techniques in ultrafast atomic and molecular physics.              

DOI: https://doi.org/10.1007/978-981-33-6084-6_10

6.     Strong-field ionization of CH 3 Cl: proton migration and association.

DOI: 10.1039/D2CP02494B

 Molecular emission dynamics from a femtosecond filament induced plasma plume .

DOI :  10.1088/2040-8986/ac528a

7.      Strong-field ionization of N2 and CO molecules using a two-color laser field. 

DOI 10.1088/1361-6455/ac9873

8.     Molecular Species Formation in Laser‐Produced Plasma. 

DOI: https://doi.org/10.1002/9781119758396.ch6   

9.     Nanosecond and Femtosecond Laser‐Induced Breakdown Spectroscopy: Fundamentals and Applications.

DOI: https://doi.org/10.1002/9781119758396.ch1

10. Strong-field induced ionization and dissociation of cis-and trans-1, 2-dichloroethylene: Cl+ and HCl+ fragments.

DOI: 10.1039/D5CP03038B

11.  Laser Induced Breakdown Spectroscopy (LIBS): Chemometrics, Environmental and Forensic Applications.  

DOI: https://doi.org/10.1007/978-3-031-90970-2_2

12. Strong field-induced three-body fragmentation dynamics of CH3Cl2+.

DOI:  10.1088/1361-6455/adac93

13. Spatiotemporal Dynamics of Femtosecond Filamentation.

DOI: https://doi.org/10.1007/978-3-031-90970-2_2  

14. Two-body skeleton fragmentation of doubly ionized C6H5Cl induced by femtosecond laser pulses .

DOI: 10.1088/1361-6455/ae68ad

15.  Orbital angular momentum (OAM) beam induced N2 filamentation:  

DOI: https://doi.org/10.1088/2040-8986/ae377c

16. Manipulation of High-Harmonic Generation Using an Engineered Two-Color Laser Field

 DOI:  https://doi.org/10.1002/cphc.202500886

17.   High harmonic generation driven by complex two-color laser fields with variable relative polarization.

This is one of the few laboratories in India engaged in cutting-edge research in ultrafast optics and molecular physics, having multiple inhouse developed spectrometers and ultrafast coherent light sources. The uniqueness of the laboratory lies on  its advanced instrumentation and the fundamental scientific questions it addresses, enabling investigations of atomic and molecular dynamics in nanoseconds to attoseconds time scale.

To understand the physics of luminescence process in natural and synthetic materials and use it for radiation dosimetry and study earth surface processes

Luminescence laboratory was started in 1977 by Professor Ashok K. Singhvi. It is the first luminescence dating laboratory of the country which pioneered in understanding the luminescence physics and apply it for geological and archaeological studies. The laboratory assisted in establishing more than 12 laboratories across India. The laboratory is constantly involved in improving the existing methodologies and exploring new domains of application of luminescence.

TL/OSL reader: Risoe TL OSL readers are used for dosimetry.
The TL OSL readers in luminescence lab are equipped with
the facilities as multispectral stimulations (green, blue, violet
and IR) and multispectral detection (UV, red, blue and visible)
along with single grain IR and green stimulation lasers, fine
grain calibration, radioluminescence, time resolved
luminescence.
Magnetic Separator: Frantz Magnetic separator is used to
separate minerals with variable magnetic susceptibility.
Grinder: Pulveriser is used to grind the sample to submicron
size.
Sieve shaker: Sieve shaker is used for separation of particles
based on their size.

• Pioneered in dating desserts across the world.
• Applied the technique to estimate cosmic exposure ages of meteorites
• Pioneered in development of spatially resolved luminescence system
• Challenged existing theory of human evolution and migration
• Applied the technique to address geological issues as, desert evolution, palaeoclimate, glaciers advancement, tectonics, tsunami, fulgurites, coastal dunes etc.

First luminescence laboratory in India

Only laboratory in India equipped with multiple sophisticated instruments having facilities as infrared radiofluorescence, single grain system with IR and green stimulation facility, violet stimulated luminescence, variable stimulation and detection assembly, EMCCD based spatially resolved luminescence system

One of the 4 laboratories of world having calibrated alpha irradiation source for luminescence efficiency estimation

One of the few laboratories in India capable of executing fine grain luminescence dating.

The main objectives of the Photonic Science Lab. are to study the interaction of the spatial structured of the optical beams with nonlinear crystal and generation of new structured optical beam tunable across UV to THz wavelength range in all time scales (continuous-wave to femtosecond). We also work on the generation of high brightness entangled photon source with hybrid and high dimensional entangled states as required for quantum communication.

We have two 10K class clean rooms under the Photonic Science Lab. The entire lab is divided into five labs involved in five different projects. In principle, we can have 10-15 people working simultaneously using the currently available infrastructure. Unfortunately, the total strength of the group is small. These five labs are dedicated to work on the study of femtosecond structured beams to generate ultrafast structured beams at different wavelengths across the EM spectra, studying the effect of spatial structures of the interacting beams in high harmonic generation process, study the effect of the spatial structure of the pump beam in the near-IR and mid-IR wavelength and transferring to THz wavelength range, the effect of continuous-wave laser beam and design of novel experimental schemes for control transfer of the orbital angular momentum of the pump beam to the generated beams and study of entangled photons, their generation and increase of the dimensionality of the entangled states and hybrid entanglement studies. The Photonic Science lab. stated in the year 2014. To date, we have published more than 37 articles in international peer-reviewed journals of a high standard and three students got their Ph.D. degree working with the existing lab. facilities.

Various laser systems including High energy Ti: Sapphire laser system, mid-IR ultrafast laser at 2360 nm, femtosecond and continuous-wave fiber lasers at 1064 nm, high coherence length continuous-wave blue laser,

Various detection systems EMCCD, ICCD, cameras covering UV to THz wavelength range

Vacuum pumps and vacuum chambers

Cleanroom facility of class 10K.

As mentioned before, the Photonic Science lab. stated in the year 2014. To date, we have published more than 37 articles in international peer-reviewed journals of a high standard and three students got their Ph.D. degrees working with the existing lab. facilities. Therefore, it is indeed very difficult to make a list of important results. The notable contributions of the Photonics Sciences are,

• We have provided the first experimental demonstration of tunable, coherent radiation in Airy intensity profile using optical parametric oscillators (OPOs) at various time scales (continuous-wave to femtosecond). Airy beams are diffraction free beams propagating along curved trajectories in free space and restoring its shape even after obstruction by small objects. Generation of Airy beam using OPO can be considered as a breakthrough in the field of structured optical beams.

• Using a single vortex beam that carries photons with orbital angular momentum (OAM), we have demonstrated controlled switching of OAM among optical beams at different wavelengths. Since OAM has infinite dimensions, OAM switching is essential in both classical and quantum communications. This is a generic and novel approach and accepted in Optica, one of the finest journals in the field of optics and photonics. 

• Phenomena of the annihilation of two photons with OAM was demonstrated and it was shown that the annihilation of OAM of two laser beams produces a new laser beam in doughnut-shaped hollow Gaussian intensity profile without OAM not in Gaussian intensity profile. This study shows the possibility of OAM manipulation (addition and subtraction) of the photons, as required for quantum computation and communication. This is the first report on OAM annihilation and a new approach to generate hollow Gaussian beams. It was accepted in Nature Scientific Reports.

• We have generated optical vortices and “perfect” vortices in the deep ultraviolet (266 nm), and visible wavelengths using nonlinear interaction of ultrafast lasers. While such beams are essential for spectroscopy, optical trapping, and tweezing, this work demonstrates the only technique to produce vortex beams at these wavelengths. As such these experimental demonstrations have started a new field of nonlinear interaction of spatially structured beams at high power/energy levels.

• It was demonstrated using spontaneous parametric down-conversion (SPDC) that the angular spectrum of the entangled photons does not depend on the OAM content of the pump beam but depends on its spatial distribution. This is the first report on SPDC photons generated using perfect vortices. We have established the fact that OAM of the vortices does not play any role in the spatial structure of the single photons.

• We have also developed a high brightness entangled photon source for long-distance free space and quantum space communication and demonstrated the possibility of generating quantum state directly from a classical state. A hybrid entangled two-photon quantum state through the SPDC of classical non-separable state of pump beam was generated as proof-of-principle. Such hybrid entangled states are used in quantum information science and supersensitive measurement of angular displacement in remote sensing.

• Some of these results such as the development of compact, high power, structured beam sources are essential for both basic research and technological applications. Similarly, a high brightness entangled photon source could be used for testing of the foundation of quantum optics. We have also developed few advance experiments including optical tweezers to trap micron-sized silica particles, broadband optical cloaking, quantum eraser, speckle interferometer, and coupling of the evanescent wave using optical fiber for outreach activities. Such experiments were demonstrated to more than 10000 students in Gujarat.

The Photonic Science Lab is a state-of-art laboratory to work on high-end research in the field of nonlinear and quantum optics. This is one of the very few laboratories in India working in the fields of experimental quantum optics. The laboratory also has active collaboration with various groups/labs of India and abroad. The photonic sciences laboratories also help P.hD. students of different Institutes and Universities of India through hands-on experiments.

Primary Objectives are 1. Satellite based quantum communication 2. Study of quantum entanglement 3. Quantum sensing and quantum metrology

This lab is involved in the study of physics and applications of singular optics i.e. phase singularity and polarization singularity in quantum domain for the purpose of quantum communication and quantum metrology.

Femtosecond Ti-Sapphire laser, High coherence length diode laser, CW Solid state laser (532 nm, 10 W), Spatial Light Modulators (SLM), EMCCD, Inverted  microscope, External cavity tuneable diode laser and single photon detectors.

The first and foremost is producing high dimensional entangled state using orbital angular momentum (OAM) modes of light, a manifestation of phase singularity in light. The lab has produced source of twisted single photons and characterized it by studying its photon statistics as well as intensity correlations. It has developed many protocols for efficient quantum key distribution and quantum teleportation using OAM modes of light.

The lab’s unique selling point is its long experience of working with optical vortex beams or OAM modes of light.

The interaction of light with matter is one of the fundamental processes that is occurring in nature. The most elementary form of this interaction is realized when a single atom interacts with a single photon. We focus on understanding and controlling these interactions with the aim to explore their possible applications in quantum technologies.

Quantum Materials & Nanophotonics Laboratory is currently focusing on the following two research areas:

I. Quantum Dots: Semiconductor quantum dots and their coupling with plasmonic cavities, Quantum dot based single photon sources and their application in quantum technologies.

II. Quantum Materials: 2D materials, Topological Insulators, Dirac semimetals, and Weyl semimetals under extreme conditions such as ultrahigh pressure (50 GPa) and ultralow temperature (4K).

Electron beam lithography system

Electron beam & Thermal evaporation system

Darkfield Microscope

Laser scanning microscope

Raman Microscope integrated with 4K Optical Cryostat & 50 GPa Diamond anvil cell

Quantum Materials & Nanophotonics Laboratory is a state-of-art laboratory to study strong light-matter coupling at room temperature. This is one of the very few laboratories in the world working to achieve and study strong light-matter coupling at room temperature.

Study of light matter interactions in different ambient, plasma dynamics and nanoparticle enhanced laser produced plasma using Laser Induced Breakdown Spectroscopy (LIBS) and plasma imaging techniques.

Laser Plasma Spectroscopy Laboratory is currently focusing on the following research areas:

1)      Synthetic generated spectrum for quantitative and qualitative analysis of samples

2)      Nanoparticle enhanced LIBS (NELIBS)

3)      Stark broadening parameters through plasma spectrocsopy

4)      Pulse Laser Ablation in Liquid (PLAL)

5)      LIBS under external perturbations

6)      Quantification of trace elements in liquid

7)      Molecular LIBS and Molecular NELIBS

8)      Estimation of plasma parameters for LTE plasma

1)      Q switched Nd: YAG laser (1064 nm and its harmonics)

2)      Excimer laser (248 nm)

3)      Czerny Turner Spectrograph

4)      Echelle Spectrometer

5)      Intensified CCD camera

6)      CMOS camera

1) Determination of Stark Shifts and Widths Using Time Resolved Laser-Induced Breakdown Spectroscopy (LIBS) Measurements

2) Effect of plasma temperature and electron number density on signal enhancement observed in nanoparticle enhanced LIBS

3) Influence of pressure and pulse energy on the expansion dynamics of nanoparticle-enhanced laser produced plasma

4) Investigation of signal enhancement in nanoparticle enhanced molecular LIBS of graphite

5) Impact of viscosity of liquid on nanoparticles synthesized by laser ablation in liquid: An experimental and theoretical investigation

6) Synergistic influence of external electric field on laser ablation in liquid: correlating nanoparticle synthesis and cavitation bubble dynamics

7) Quantitative analysis of trace elements in liquid samples using laser induced breakdown spectroscopy

8) Quantitative estimation of elemental composition employing a synthetic generated spectrum

The Laser Plasma Spectroscopy Lab is a state-of-art laboratory to work on LTE plasma, and plasma plume dynamics.