Centre National De La Recherche Scientifique

Sorbonne Université

Ecole Normale Superieure

Université Paris Diderot-Paris 7

Universite Paris Cité

Ecole Normale Superieure De Paris

Sukhdeep Dhillon

Kenneth Maussang

Jerome Tignon

Feihu Wang

Nathan Jukam

Hanond Nong

Tobias Fobbe

A photoconductive switch for generating or detecting terahertz radiation (TR) is provided. The photoconductive switch may comprise at least a first and a second pair of electrodes (E, E, E) on a surface (SS) of a photoconductive substrate, wherein the electrodes of the first pair are separated by a first gap comprising at least a plurality of first rectilinear sections (G) extending along a first direction (x) and the electrodes of the second pairs are separated by a second gap comprising at least a plurality of second sections (G) extending along a second direction (y), different from the first direction. The photoconductive switch may further comprise a patterned opaque layer (PML) selectively masking portions of the gaps between the electrodes. Methods and devices for generating and detecting terahertz radiation comprising such photoconductive switches are also provided.

Generation and detection of terahertz radiation with an arbitrary polarization direction

A laser source for emitting radiation in a given emission spectral band, centered on a given emission angular frequency, the central emission angular frequency is provided. The laser source comprises a laser cavity comprising a gain section having a known frequency dependent Group Delay Dispersion, and a GTI mirror arranged at one end of the gain section, having a known frequency dependent Group Delay Dispersion. The gain section and the GTI mirror are formed into a same laser medium, the laser medium having a known frequency dependent Group Delay Dispersion, and the gain section and the GTI mirror are separated by a gap of predetermined width filled with a dielectric medium thus forming a two parts laser cavity. Further, the GTI GDD at least partly compensates the sum of the Gain GDD and the material GDD in the emission spectral band.

Laser source and method of manufacturing such

The present invention relates to a metal-metal interdigitated photoconductive antenna that generates and/or detects terahertz waves, the photoconductive antenna comprising at least one substrate () and at least one electrode () on the front face of the substrate (), wherein said photoconductive antenna comprises at least one layer () formed of a material reflective to terahertz waves, said layer () extending below the front face of the substrate () at a distance lower than the wavelength; and it comprises an interdigitated geometry on said front face of the substrate () comprising a first metallization layer of 5 nm Cr and 150 nm Au for the interdigitated electrodes (), equally spaced by a distance &#x394;, is made on said front face of the substrate (); a 500 nm-thick layer of SiO() deposited over the first metallization layer; and a second metallic layer composed of metallic fingers () covering gaps with a periodicity double that of the distance &#x394;.

Photoconductive antenna for terahertz waves, method for producing such photoconductive antenna and terahertz time domain spectroscopy system

Growing community of inventors

Bourg la Reine, France

Sukhdeep Dhillon