iPCA working principleAn extended gap along the finger electrodes of the iPCA is illuminated by a short pulse laser beam. By using the microlens array only every second gap between the finger structure is excited by the laser. The fill factor of the lens array of 73.5 % ensures, that nearly the total optical laser energy is used for excitation of carriers. Despite of the large emitting area the needed voltage for the carrier excitation is low (< 35 V) because of the small gap of only 5 μm. The coherent excitation of the single emitters located at every microlens spot results in a constructive interference of the radiated THz waves in the far field.
Mounting:
iPCA chip, size 4 mm x 4 mm, thickness 625μm, mounted on 25.4 mm diameter black aluminium mount with prealigned hyperhemispherical silicon lens ? 12 mm and prealigned fused silica lens array, size 2 mm x 2 mm, and 1 m coaxial cable (RG 178) with BNC or SMA connector.