Silicon photonics is a matured technology today for optical communication transceiver industries. Besides transceiver, other upcoming application areas for silicon photonics are depicted in the cartoon figure below. Present research focus of the CPPICS team is mainly cantering around design, demonstration and packaging of photonic chips for advanced microwave and quantum photonic applications.

One of the prime focuses of our group is the design of novel photonic devices for various applications such as computations and sensing to perform power splitting/combining, filtering, modulation, photon pairs generation/manipulation and detection. Apart from silicon platform, silicon nitride is also explored to fabricate devices spanning a multitude of functionalities. Devices can be categorized broadly into active and passive, depending on whether doping (n or p type) is present or not.

Our current focus is on the following research topics:

  • Passive Devices: Passive devices constitute waveguides, splitters/combiners, MUX/DMUX, crossings, bends which are routing essentials, as well as stand-alone devices like microring/microdisc (MRR/MDR) resonator, Sub-wavelength gratings (SWG), Mach Zehnder interferometer (MZI), Distributed Bragg reflector (DBR), DBR cavity and much more.
  • Active Devices:
    • High-speed optical modulators
    • Waveguide integrated photodetector
Microwave

In the process of scaling photonic circuits, an in-depth exploration of fundamental photonic devices is of paramount significance to realize large-scale circuits. The development of compact models for individual devices is a pivotal step, enabling photonic designers to create process design kits (PDKs). These PDKs derived from the foundries, empower end-users to efficiently design the specific photonic circuits. In addition, accurate compact models of individual components will eventually enable photonic circuit designers to realize electro-optic circuits for applications like LIDAR, neuro-morphic computing, and quantum computing.

Our current focus is on the following research topics:

  • Development of compact models of different active and passive integrated photonic components for electro-optic co-simulation in a single platform
  • Wafer Scale Analysis for yield prediction, variability analysis, and design optimization from analysis of wafer scale characterization data

Microwave

Owing to the success of high-speed silicon photonic transceivers in the data centres, demand for similar products in several other fields has emerged. Microwave photonics is one such field where the THz bandwidth of photonics can overcome the limitations in conventional microwave components. The futuristic communication systems target to operate in the high frequency (10s of GHz) to meet the ever-increasing demand of data consumption. The design of microwave components such as filters, oscillators, phase shifters to operate at these frequencies with a small footprint (cm x cm) is challenging.

Our current focus is on the following research topics:

  • Demonstration of a packaged photonic RF filter chip, over a wide range of frequencies (up to 40 GHz), with the necessary electronic interfacing with the optical signal processor,
  • Development of a fully packaged RF filter with a tunable bandwidth (0.1-1% of the central frequency)
  • Realization of Optoelectronic oscillators and on-chip photonic beamformer for mm-wave applications
Microwave

Our current focus is on the following research topics:

  • Quantum Photonic Sources: Photon pair generation through spontaneous four-wave mixing (FWM) in silicon waveguides or micro-ring resonators stands as a pivotal requirement in the realm of large-scale integrated quantum photonics.
  • Microwave
  • Quantum Random Number Generator: Quantum Random Number Generator (QRNG) is a type of TRNG where the source of randomness is generated from quantum-mechanics driven physics, which is by nature having very high unpredictability. We have exploited the well developed CMOS technology in our lab to generate real-time truly random bit streams on silicon (SOI) platform.
Microwave