Related Experiment Video
Updated: Jun 12, 2026
09:01
High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings
Published on: April 16, 2017
Temperature dependent nonlinearity effects of a QED-200 detector in the visible
Applied Optics
|June 26, 2010
Abstract:
The spectral response of the United Detector Technologies model QED-200 quantum efficiency detector, along with that of other photodiodes, has been measured for two different wavelengths in the visible. The QED shows a strong temperature dependent response at certain power levels. It is shown that the effect comes from an increase in internal quantum efficiency due to a supralinearity effect at power levels of ~1 mW.
Related Concept Videos
02:26Photoelectric Effect
When light of a particular wavelength strikes a metal surface, electrons are emitted. This is called the photoelectric effect. The minimum frequency of light that can cause such emission of electrons is called the threshold frequency, which is specific to the metal. Light with a frequency lower than the threshold frequency, even if it is of high intensity, cannot initiate the emission of electrons. However, when the frequency is higher than the threshold value, the number of electrons ejected...
01:27Atomic Spectroscopy: Effects of Temperature
Atomization, converting samples into gas-phase atoms and ions, is essential for atomic spectroscopy. The flame temperature required for atomization affects the efficiency of the atomic spectroscopic methods by increasing the atomization efficiency and the relative population of the excited and ground states.
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
01:14UV–Vis Spectrometers
The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell. Samples for...
01:15High-Performance Liquid Chromatography: Types of Detectors
The role of the detectors in High-Performance Liquid Chromatography (HPLC) is to analyze the solutes as they exit from the chromatographic column. The detector recognizes the solute's property and generates corresponding electrical signals, which are converted into a readable graph of the detector's response versus elution time called a chromatogram at the computer. There are several types of HPLC detectors, each with its own advantages and limitations, depending on the analyte properties and...