Fig. 1: Schematic diagram of the experimental layout.
From: Terahertz strong-field physics in light-emitting diodes for terahertz detection and imaging
a THz pulses for the LED detection are generated in a LN crystal via tilted pulse front technique. Two THz polarizers are used for tuning THz energies illuminated onto LEDs. The LEDs examined in our experiments include various colors of blue, white, green, yellow, and red. A single-shot spectrum encoding method is employed for THz temporal wave and spectrum characterization. LEDs are positioned at the focal plane and photovoltaic signals are recorded by an oscilloscope. b Zoom-in picture of LEDs which are mounted on a rotational printed circuit board for further investigating the THz polarization-dependent photoresponses. c THz field induced photovoltaic signals in LEDs via impact ionization are monitored by an oscilloscope. The anode of the LED is connected to the positive electrode of the oscilloscope and vice versa. d Typical THz temporal waveform recorded by the single-shot measurement. e Visible light LED lamps used for THz detection. HWP: half-wave plate; LN: lithium niobate; OAP: 90° off-axis parabolic mirror; P1 and P2: THz polarizer; PCB: printed circuit board; QWP: quarter wave plate; GP: Glen-prism.
