Photoconductive Devices (PC) are detectors based on the photoconductive effect. Infrared radiation generates charge carriers in the semiconductor active region decreasing its resistance. The resistance change is sensed as a voltage change by applying a constant current bias. The optimum bias current is specified in the Final Test Report and depends on the detector size, operating temperature and spectral characteristics. PC detectors in our offer comes with different spectral response. Ask our Sales Department for any details!
Photovoltaics Devices (PV) are detectors based on the photovoltaic effect. Infrared radiation generates charge carriers in the semiconductor active region thanks to generation phenomenon. Specially prepared layers of semiconductor are constructed with electrical contacts which can enable measuring the generated electrical signal. Thus light can be measured. PV detectors comes with different spectral response. Ask our Sales Department for any details!
Optical immersion is achieved by using high refractive index microlenses in order to improve performance of the devices but may limit acceptance angle. Optical immersion is a monolithic integration of a detector element with hyperhemispherical microlens (basic configuration) that makes optical linear size of detector 11 times larger compared to its physical size. This results an improvement of D* by one order of magnitude and electric capacitance by a factor of two orders of magnitude less compared to a conventional detector of the same optical area. If you are not sure about whether to use immersion lens in your system or not, be sure to ask our Sales Department for guidelines!
Operation of thermoelectric coolers is based on Peltier effect. Two-, three- and four-staged thermoelectric cooler are available. TEC is biased with DC current supply. The parameters of TEC depend on temperature of the hot side of cooler. It is typically specified for 300K.
The broad line of preamplifiers is specifically designed for VIGO HgCdTe or III-V detectors. Each preamplifier is optimized to work with a particular type of detector. The preamplifier ensures stable work in all conditions and the highest signal to noise ratio of the whole system. There is no such thing as the best preamplifier. Each of the preamplifiers is specialized in its own category. For example µIP preamplifier is very small, PIP preamplifier can be programmable and FIP preamplifier can be very fast. For more information about preamplifiers for your applications ask our Sales Department!
VIGO thermoelectrically cooled detectors are typically provided with:
- 3° wedged Al2O3 windows (wAl2O3)
- 3° wedged ZnSe AR coated windows (wZnSeAR)
3° wedge prevents “fringing” – interference from stray back reflections. We offer windows optimized for different spectral bands, as well. VIGO detector windows is presented in the figure below.
Windows can be anti-reflection (AR) coated on two surfaces. We can mount windows provided by the user as well as filters. For more information contact our Sales Department!
We bias our PV detectors in cases when the higher speed of the detector is needed. If a higher frequency band is required, we need to speed up the detector (by biasing). Preamplifiers for biased detectors must be AC coupled.
There is a possibility to cool it down to liquid helium temperature. As for the opposite side, we can heat it up to 200°C what makes it convenient for some of the applications. Ask Sales Department for our brand new product based on III-V materials!
Lifetime strongly depends on temperature of storage and temperature of operation. At normal temperatures lifetime exceed 5 years but many customers are using our detectors for more than 10 years in laboratory applications. Usually at field applications, mechanical wear-out of optoelectronic system is main reason for end-of-life replacements.