PCA-44-06-10-800-x
Photoconductive THz antenna for laser excitation wavelengths λ ~ 500 nm … 850 nm
PCA – Photoconductive Antenna
Spectral performance
This antenna shows a high sensitivity especially at low frequencies. But if the antenna is used as emitter, then multiple pulses can be measured as a result of reflections of the electrical pulse within the antenna structure. Therefore we recommend the use of this butterfly antenna mainly as detector.
Antenna parameters
Parameter
minimum ratings
standard
maximum ratings
Dark resistance
2 GΩ
3 GΩ
5 GΩ
Voltage
20 V
30 V
Optical mean power
20 mW
30 mW
Pulse fluence
200 µJ/cm2
300 µJ/cm2
Attention: The F-number of the optical lens focusing the laser beam onto the antenna gap must be larger then a certain value to avoid too high pulse fluency. This means, that the minimum diameter of the focused beam waist must be about 120 % of the gap distance g. For a Gaussian beam the minimum focus length fmin of the optical lens can be estimated as
with g – gap distance of the antenna
λ - laser wavelength
D – diameter of the laser beam hitting the focusing lens.
For λ = 0.8 µm and g = 6 µm the minimum possible F-number of the lens is fmin/D = 7
Dark current voltage characteristic
Antenna design
Main PCA data
- Laser excitation wavelength 800 nm
- Antenna gap: 6 µm
- Antenna length 44 µm
- Antenna chip size 2 mm x 2 mm
Order information
PCA-44-06-10-800-x Photoconductive antenna
length l = 44 µm
gap g = 6 µm
width w = 10 µm laser
wavelength λ= 800 nm (500 nm … 850 nm)
x denotes the type of mounting as follows:
x = 0 unmounted chip 2 mm x 2 mm with 4 bond contact pads
x = h mounted on an Al disc with 25.4 mm φ and hyperhemispherical silicon substrate lens, 1m coaxial cable with BNC or SMA connector
x = a mounted on an Al disc with 25.4 mm φ and aspheric focusing silicon substrate lens, 1m coaxial cable with BNC or SMA connector
x = c mounted on an Al disc with 25.4 mm φ and aspheric collimating silicon substrate lens CL-12 for 12 mm THz beam diameter, 1m coaxial cable with BNC or SMA connector
x = h-f fiber coupled antenna with hyperhemispherical silicon substrate lens
x = l with aspheric focusing optical lens for free space laser excitation
x = p with preamplifier for detector antenna
描述 [描述] • Antenna length l: 44 µm<br />• Gap distance g: 6 µm<br />• Gap width w: 10 µm<br />• Laser wavelength λ: ≤ 800 nm