Enhanced two-photon-absorption using sub-wavelength antennas

B. Vest (1) , B. Portier (2) , F. Pardo (2) , N. Péré-Laperne (2) , E. Steveler (2) , J. Jaeck (1) , C. Dupuis (2) , N. Bardou (2) , A. Lemaître (2) , E. Rosencher (1) , R. Haïdar (1) , J.L. Pelouard (2)

1 ONERA - The French Aerospace Lab [Palaiseau]
2 LPN - Laboratoire de photonique et de nanostructures

Degenerate two-photon absorption (TPA) is investigated in a 186 nm thick gallium arsenide (GaAs) p-in diode embedded in a resonant metallic nanostructure. The full device consists in the GaAs layer, a gold subwavelength grating on the illuminated side, and a gold mirror on the opposite side. For TM-polarized light, the structure exhibits a resonance close to 1.47 μm, with a confined electric field in the intrinsic region, far from the metallic interfaces. A 109 times increase in photocurrent compared to a non-resonant device is obtained experimentally, while numerical simulations suggest that both gain in TPA-photocurrent and angular dependence can be further improved. For optimized grating parameters, a maximum gain of 241 is demonstrated numerically and over incidence angle range of (−30°; +30°). This structure paves the way towards low-noise infrared detection, using non-degenerate TPA, involving two photons of vastly different energies in the same process of absorption in a large bandgap semiconductor material.

Mots clés: infrared; two photon absorption; nanostructure; photodiode; subwavelength; plasmonics; confinement

Domaines: Optique / photonique

B. Vest, B. Portier, F. Pardo, N. Péré-Laperne, E. Steveler, et al.. Enhanced two-photon-absorption using sub-wavelength antennas. SPIE Photonics West 2015, Feb 2015, SAN FRANCISCO, United States. ⟨hal-01121728⟩