Tunable ultrasharp terahertz plasma edge in a lightly doped narrow-gap semiconductor

Terahertz radiation emitters from narrow-gap semiconductors

Giant tunable Faraday effect in a semiconductor magneto-plasma for broadband terahertz polarization optics.

We report on a giant Faraday effect in an electron plasma in n-InSb probed via polarization-resolved terahertz (THz) time-domain spectroscopy. Polarization rotation angles and ellipticities reach as large as π/2 and 1, respectively, over a wide frequency range (0.3-2.5 THz) at magnetic fields of a few Tesla. The experimental results together with theoretical simulations show its promising abili...

Weak localisation theory for lightly doped semiconductor quantum wires

A weak localisation theory for a semiconductor quantum wire, which has a width of the order of the Fermi wavelength, is presented. In our model the electronic motion is essentially one-dimensional and the localisation length L, is much larger than the mean free path I , so that, in contrast to conventional theories a non-localised quantum wire with a total length L < L, but much larger than I i...

Interference-induced terahertz transparency in a semiconductor magneto-plasma

Maximum modulation of light transmission occurs when an opaque medium is suddenly made transparent. This phenomenon occurs in atomic and molecular gases through different mechanisms1,2, whereas much room remains for further studies in solids3–5. A plasma is an illustrative system showing opacity for low-frequency light, and light–plasma interaction theory provides a universal framework to descr...

Tunable narrow-band terahertz generation from periodically poled lithium niobate

We describe a technique for generating tunable narrow-band terahertz radiation via optical rectification in periodically-poled lithium niobate. Frequency tuning is accomplished by spatially chirping the domain width laterally to the beam propagation direction, and adjusting the temperature of the sample. We demonstrate tuning over a continuous range from 0.8 to 2.5 THz. The bandwidth of the ter...