Photonic crystals modify the emission properties of integrated emitters by altering the local density of states, thereby controlling the emission rate and directionality of spontaneous emission. In this work, Zn-alloyed CsPbBr3 nanocrystals (NCs), possessing high (96%) intrinsic quantum yield, are integrated into a one-dimensional photonic crystal (1DPhC) to investigate Bloch surface wave mediated emission enhancement and directionality. Polarized, 42-fold enhanced directional emission (\textless4° angular spread), along with an increased spontaneous emission rate, is observed when the NCs are embedded in the 1DPhC.
@inproceedings{panditHighlyDirectionalEmission2026,series={Topical {Meeting} - {Nanophotonics}},address={Tampere, Finland},title={Highly {Directional} {Emission} of {Zinc}-{Alloyed} {CsPbBr}<sub>3</sub> {Perovskite} {Nanocrystals} in {Bloch} {Surface} {Wave} {Engineered} {Photonic} {Crystals}},volume={389},copyright={https://creativecommons.org/licenses/by/4.0/},issn={2100-014X},url={https://www.epj-conferences.org/10.1051/epjconf/202638902011},doi={10.1051/epjconf/202638902011},urldate={2026-10-06},booktitle={{EPJ} {Web} of {Conferences}},publisher={EDP Sciences},author={Pandit, Somnath and Murali, Rahul and Raavi, Sai Santosh Kumar and Guha, Prasanta Kumar and Bhaktha, Shivakiran B. N.},year={2026},pages={02011}}
2025
SAMDeV 2025
Bloch Surface Wave Enhanced Emission in Perovskite Embedded Photonic Crystal
Somnath Pandit, Rahul Murali, Prasanta Kumar Guha, Sai Santosh Kumar Raavi, and Shivakiran Bhaktha B.N.
Bloch surface wave (BSW) mode of photonic crystal (PhC) has very high energy confinement on the surface of the structure. Perovskite nanocrystals (NCs) having excellent optical properties like narrow emission linewidth, very high quantum yield ( 90%), exceptional colour brilliance and photoluminescence (PL) stability are of great interest in optoelectronics [3]. In this work, CsPbBr3 NCs coupled with BSW mode is extracted through prism coupling to get highly directional (4^o^ divergence) and enhanced emission ( 40x), due to weak coupling and modified local optical density of states.
2024
CLEO 2024
Spatial Correlation of Whispering Gallery Modes in an Active Micro-Bottle Resonator
Subhajit Dutta, Somnath Pandit, and B. N. Shivakiran Bhaktha
The spatio-spectral imaging of active micro-bottle resonator (MBR) is performed and the spatial correlation of the whispering gallery modes (WGMs) are investigated in a dye-doped poly (methyl methacrylate) (PMMA) coated silica micro-bottle resonator.
2023
CLEO 2023
Tamm Mode-Aided Amplified Spontaneous Emission in One-Dimensional Photonic Crystal Super-Tamm Structure
Sudha Maria Lis S, Somnath Pandit, Someprosad Patra, Debamalya Banerjee, and Shivakiran Bhaktha B N
The optical Tamm mode-aided amplified spontaneous emission in a super-Tamm structure consisting of a silver (Ag) thin film deposited on dye-doped polyvinyl alcohol (PVA) layer coated on a SiO2/TiO2 one-dimensional photonic crystal structure is presented.
2022
NLS-31
Laser Micromachined Moiré Pattern Strain Sensors on Polymer Membrane
Sarbojit Mukherjee, Somnath Pandit, R Hemant Kumar, Khanindra Pathak, and Shivakiran Bhaktha B.N.
Moiré technique is one of the highly sensitive non-contact method to measure surface deformations due to strain. In literature, Moiré patterns are made using holographic photolithography, electron beam lithography, focused ion beam (FIB) lithography and nanoimprint lithography (NIL). Some of these techniques need very expensive and precise equipments like vibration isolation platform, nano stage, which makes fabrication and mass manufacturing difficult. Here, we propose picosecond laser micromachining as a reliable technique for embedding optical microstructures such as gratings at various depths of a material. The proposed membranes can be used as strain sensors for health monitoring of various structures, importantly in underground mines wherein all-optical sensors are in great demand.
COPaQ 2022
Spectral Narrowing of Amplified Spontaneous Emission in One- Dimensional Photonic Crystal Super Tamm Structure
Sudha Maria Lis S, Somnath Pandit, Someprosad Patra, Debamalya Banerjee, and Shivakiran Bhaktha B N
In this work, studies on the optical Tamm mode of a super-Tamm structure consisting of a silver (Ag) thin film deposited on dye-doped polyvinyl alcohol (PVA) thin film coated on a SiO_2/ TiO2 one-dimensional photonic crystal (1DPhC) structure are presented. The spectral narrowing of the Tamm state aided amplified spontaneous emission from the structure is attributed to the strong confinement of Tamm mode in the DCM dye doped PVA layer sandwiched between 1DPhC and Ag thin film.