The hybrid photodetector (HPD) is a proximity electro-vacuum device with photocathode and solid-state element – electron-sensitive CCD.
In HPD for NIR range a photocathode with drawing electrical field based on InP/InGaAs structure is used, that provides high sensitivity in range of 950 ÷ 1650 nm.
When photoelectrons hit array with energy, higher than 2-3 keV, generation of electron-hole pairs occurs in silicon, and gain of signal increases in several hundred times.
Because of signal gain in electron-sensitive CCD array HPD will have sensitivity of 1-2 order higher than solid-state analogues.
In HPD the whole signal photoelectron flow from photocathode reaches array, there are no intermediate signal converting, so noise factor is about 1,1. Besides, there are no fiber-optics elements in HPD, which decrease device radiation hardness.
The device is recommended to apply in low light level portable TV equipment, observation systems for aircrafts, etc.
|Spectral range, nm||950÷1650|
|Photocathode quantum efficiency in maximum, %||2-10|
|Photocathode voltage, kV||4-5|
|Sensitive area size, mm||13,1×9,8|
|Number of pixels||768×580|
|Pixel size, μm||17×34|
|Threshold irradiation, W/pixel (W/cm2)||~2·10-13 (~3,4·10-8)|
|Device diameter, mm||60|
|Device height, mm||23|
RELATIVE SPECTRAL RESPONSE CHARACTERISTICS
It is possible to manufacture a photodetector based on HPD, including hybrid device, power supply sources and signal processing electronics.