Summary:

Day 1 (04^th March 2025)

1. Introduction to solid state lasers: Gain medium, pumping methods, thermal effects, resonator design, etc.
   Duration: 60 minutes (Dr. B. N. Upadhyaya), 9:30 hrs. to 10:30 hrs.
   
   
2. Lamp pumped solid state lasers: Basics and laser technology for CW and pulsed Nd:YAG lasers
   Duration: 60 minutes (Dr. B. N. Upadhyaya), 10:30 hrs. to 11:30 hrs.
   
   Tea break: 11:30 hrs. to 12:00 hrs.
   
   
3. Diode pumped solid state lasers: Basics of DPSSL and laser technology for CW and pulsed lasers, SHG, Q-switch. Mode locking, etc.
   Duration: 90 minutes (Shri Amarjeet Singh), 12:00 hrs. to 13:30 hrs.
   
   Lunch break: 13:30 hrs to 14:30 hrs.
   
   
4. Fiber Lasers:
   1. Fiber optic components: Working and configuration of different fiber components for fiber lasers
      Duration: 90 minutes (Dr. P. K. Mupkopadhyay), 14:30 hrs. to 15:45 hrs.
   2. CW & pulsed fiber lasers: Basics of fiber lasers (gain medium, single and double clad fibers, photonic crystal fibers), CW, QCW and Q-switched fiber lasers, physical limitations, fiber laser technology
      Duration: 90 minutes (Dr. B. N. Upadhyaya), 15:45 hrs. to 17:15 hrs.

 Day 2 (5^th March 2025)

5. Ultrafast fiber lasers: Basics of mode locking in fiber lasers, technology of mode locking in fiber lasers, characterization techniques, ultrafast fiber laser development activity at RRCAT, etc.
   Duration: 210 minutes (Dr. P. K. Mupkopadhyay + Dr. C. P. Singh + Dr. Pradeep Kumar Gupta), 10:00 hrs. to 13:30 hrs.
   
   Lunch Break: 13:30 hrs. to 14:30 hrs.
   
   
6. Lab visit and demonstration of solid state lasers (R&D Block-G)
   Duration: 180 minutes, 14:30 hrs. to 17:30 hrs.

Summary: 

Optical properties of noble metal nanoparticles / nanostructures governed by the so-called surface plasmon resonance effects have evoked intensive investigations in recent times due to their fundamental nature and potential applications. Biomedical and chemical sensing, bio-molecular manipulation, energy harvesting, contrast enhancement in optical imaging, surface enhanced spectroscopy, development of nano-optical devices, optical information processing, plasmonic metasurfaces and data storage, switching, lasing, filters and robust color display, nonlinear and slow-light devices, invisibility cloaking are just a smattering of its numerous potential applications.  Besides applications, a number of intriguing and exotic effects associated with the interaction of light with spatially structured plasmonic nanostructures (the so-called plasmonic metamaterials) have also been observed. Extraordinary transmission of light (EOT), Electromagnetically induced transparency (EIT) and absorption (EIA) in plasmonic metamaterials, coherent perfect absorption of light (CPA) and super scattering,  Spin orbit interaction (SOI) and Spin Hall (SH) effect of light, Optical Rashba effect, coupled plasmons and plasmonic Fano resonances, Optical bound states in continuum (BIC),  nonreciprocity in reflection from spatial Kramers–Kronig medium are some of the recently discovered intricate plasmonic effects, which also potential applications for the next generation nanophotonic devices. Most of the aforementioned nontrivial optical effects have been observed in the interaction of nanostructured metamaterials with homogeneous optical fields of light (such as plane waves or Gaussian beam). There has been growing interest in tailoring some of these effects using the interaction of structured optical fields (carrying intrinsic of extrinsic orbital angular momentum -OAM) or structured polarization (Spin angular momentum of light -SAM) of light with nanostructured metamaterials. These have opened up a new paradigm of the next generation nano-photonic metadevices to control and manipulate light at nanometer length scale. The growing maturity of related fields in photonics and optoelectronics have played a key role in structuring the light, its topological and geometric properties, its polarization and angular momentum states on desired fashion. It has opened up an emerging and fast- growing field, namely, ‘Spin-orbit nanophotonics’, having a plethora of applications in multifunction and on-chip integrable photonic devices, optical metasurfaces and data storage and in both classical and quantum information processing, optical computing, etc. The intent of the short course is to summarize current state of research of this promising field that is breaking new grounds into the domain of nano-photonics, facilitate insight and understanding of the recent trends and findings, indicate the outstanding challenges, and point toward the future of this promising field.

Topics to be covered

• Introduction to nanophotonics and plasmonics
• Introduction to nontrivial optical phenomena like EOT, EIT, EIA, BIC,CPA, Plasmonic Fano resonances etc.
• Structured light and Angular momentum of light
• Spin orbit interaction (SOI) of light and geometrical phase

Spin  and orbital angular momentum-controlled photonics using metasurfaces and structured light

Course Coordinator: 

Nirmalya Ghosh, PhD
Professor,
Fellow, Indian Academy of Sciences (FASc.),
Fellow, National Academy of Sciences India (FNASc.),
Department of Physical Sciences,
Centre of Excellence in Space Sciences India (CESSI),
PI, bio-Optics and Nano-photonics (bioNap) Laboratory,
IISER – Kolkata, Mohanpur – 741246, India.,
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.