PCA-photoconductive antenna

PCA - Photoconductive antenna

PCA - Photoconductive antenna as terahertz transmitter

A photoconductive antenna, consisting of a low temperature grown GaAs or InGaAs film covered with metallic contacts can be used as an optical excited broadband terahertz emitter for time domain measurements or as photomixer. Typically an alternating voltage is supplied to the electrical contacts of the transmitter antenna to allow a lock-in measurement. There are at least two important antenna parameters: the length l and the gap distance g. The length l determines the prefered emitted frequency at theresonance condition. The gap of the transmitter antenna between the metallic contacts can be larger than the laser spot diameter.
The PCA can be accomplished with a hyperhemispherical or an aspheric silicon substrate lens to increase the extraction efficiency for THz waves.

PCA terahertz receiver 

The PCA receiver has the same design as the transmitter. The optimal gap between the metallic contacts is about equal to the laser spot diameter. A current amplifier connected to the antenna contacts delivers a signal proportional to the terahertz electric field strength.

iPCA - large area interdigital photoconductive antenna 

The iPCA is designated as high power THz transmitter, but can be used also as sensitive large area THz receiver. The interdigital antenna with a proprietary lens array converts high power laser pulses up to mean power levels of 5 W with a high power conversion efficiency of ~ 10^-4 into broadband THz pulses

Contents

• Butterfly antenna
• Parallel line antenna
• Bow-tie antenna
• SPCA - logarithmic spiral antenna
• Bow-tie antenna with finger gap structure

Wavelength :800nm,1060nm,1550nm