This file contains the datatset for "Optical Gating of graphene on Photoconductive Fe:LiNbO3" by J. Gorecki, V. Apostolopoulos, J.Y. Ou, S. Mailis, N. Papasimakis.

This dataset supports the publication:E. Mavrona, et al (2018). Intrinsic and photo-induced properties of high refractive index azobenzene based thin films [Invited]. Optical Materials Express 8, 420-430

Data, code and plots used in the paper, "Temperature dependent polarity inversion in double-metal terahertz emitters "Submitted to be published in Electronics Letters.The temperature dependent polarity inversion in double-metal THz emitters was investigated. Double-metal emitters utilising different metal pairings and single edge metal emitters were cooled in a helium flow cryostat and their THz emission was measured over a range of temperatures. Most emitters, including those with insulating layers between the metal and semiconductor, exhibit a flip in polarity of their THz emission between 50 and 100 K. This shows the inversion is a trait intrinsic to the semiconductor and not influenced by the metallic contact on the surface.

Dataset supports:Chen Sverre, T. et al (2018). Continuous repetition rate tuning from 960 MHz to 1.72 GHz of a sub-300 femtosecond mode-locked semiconductor disk laser. Applied Physics Letters, 113(16), [161106].Vertical External Cavity Surface Emitting semiconductor Lasers rely on Semiconductor Saturable Absorbing Mirrors for mode-locking, allowing laser cavities to be designed far from stability limits. We have harnessed this feature to study repetition rate tunability. The cavity element separations were determined by a coded cavity design protocol based on cavity round trip matrix calculations. We produced a sub-300-fs near transform-limited pulse train with a repetition rate of 0.96 MHz - 1.72 GHz, at 1035 nm and average power of 50 mW.

We show that, when large area multiplex terahertz semiconductor emitters that work on diffusion currents and Schottky potentials are illuminated by ultrashort optical pulses, can radiate a directional electromagnetic terahertz pulse which is controlled by the angular spectrum of the incident optical beam. Using the lens that focuses the incident near infrared pulse, we have demonstrated THz emission focusing in free space, at the same point where the optical radiation would focus. We investigated the beam waist and Gouy phase shift of the THz emission as a function of frequency. We also show that the polarization profile of the emitted THz can be tailored by the metallic patterning on the semiconductor, demonstrating radial polarization when a circular emiter design is used. Our techniques can be used for fast THz beam steering and mode control for efficiently coupling to waveguides without the need for THz lenses or parabolic mirrors.