Nonlinear metasurface on silicon photodiode for infrared detection

Laboratory: MPQ 

Address: 10 Rue A. Domon et L. Duquet – 75013 Paris 

Supervisor of internship and/or PhD thesis: Giuseppe LEO 

Tel: 01 57 27 62 27, 06 67 44 38 73 

e-mail: giuseppe.leo@u-paris.fr 

Scientific project:

In the last decade metasurfaces, that is 2D arrays of optical nanoantennas with sub-wavelength size and separation, revolutionised the field of optics. They also showed their potential in the nonlinear regime, especially in connection with the huge non-resonant (2) of III-V semiconductors in the short-wavelength infrared (SWIR) spectral range. In this domain, MPQ recently achieved second harmonic generation (SHG) with phasefront control in a nonlinear metasurface (NLMS), with 10-5 conversion efficiency (Fig. 1). To improve this figure, relevant efforts are currently being devoted by the NLMS community, mainly by exploiting the narrow resonances of quasi-bound states in the continuum associated to nonlocal resonant modes and strong near-field coupling between meta-atoms.
In this rapidly evolving context, this internship/PhD project aims to tackle an old problem of nonlinear optics, namely the efficient up-conversion of infrared radiation into the silicon (Si) absorption band, with a device allowing for ultrafast detection of SWIR radiation. Building upon the above breakthrough, we will do so by integrating a NLMS to a Si avalanche photodiode (APD). More specifically, following also our demonstration of NLMS for SWIR-to-visible upconversion via SFG, we will address signals with wavelength beyond the fast-detection limit of InGaAs, by combining a Si APD with an AlGaAs-on-insulator NLMS. The latter will mix a signal at S≈1.8 µm with a pump at P≈1.3 µm to perform sum frequency generation (SFG) at SFG≈0.75 µm, i.e. at about the maximum spectral responsivity of Si.
We aim at two synergic objectives that will disclose for the first time the full potential of NLMSs with a SFG-based integrated device for ultrafast SWIR detection: 1) high-Q NLMS integrated directly on a Si APD; and 2) large-area NLMS-based lens integrated on a Si APD. In the former case we will demonstrate a uniform nonlocal NLMS that will be will be directly integrated on the APD; in the latter, SFG and focusing will be provided by a NML separated from the APD by a transparent spacer with an optical thickness equal to its focal length.
This internship/PhD will take place at MPQ, in collaboration with CEA (technology, photodetection) and INRIA (advanced nonlocal design; inverse-design optimization of single meta-atoms or meta-molecules).

Methods and techniques: photonic modelling, nanofabrication, experimental optics
Possibility to go on with a PhD ? YES
Envisaged fellowship ? YES (ANR project)