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US 5,326,984 AGranted
Electromagnetic wave detector
AssigneeThomson-CSF
InventorsEmmanuel Rosencher, Philippe Bois
Life of this patent
Estimating the term…
Abstract
An electromagnetic wave detector comprises a stack of quantum wells included between an ohmic contact and a rectifier junction which may be a barrier (Al.sub.y Ga.sub.1-y As) with a forbidden band width that is greater than that of the barriers of the quantum wells.
Claims19
An electromagnetic wave detector, comprising:
- a stack of layers of different materials having different forbidden band gaps, so as to constitute a stack of quantum wells, the stack of layers having first and second major surfaces and an ohmic contact on the first major surface and a rectifying junction on the second major surface;
- and
- means for applying a voltage of alternating polarity across the ohmic contact, the stack of layers, and the rectifying junction.
An electromagnetic wave detector for detecting electromagnetic waves having a first photon energy, comprising:
- a semiconductor superlattice structure;
- a current detector;
- a voltage source;
- a switching network;
- wherein the semiconductor superlattice structure and the current detector are coupled in series with one another and the switching network is operable to couple the voltage source in series with the semiconductor superlattice structure in either of a first polarity or a second polarity;
- and
- wherein the semiconductor superlattice structure comprises a plurality of quantum wells wherein each of the plurality of quantum wells has at least a first bound energy level and the energy of the first bound energy level in each of the quantum wells is the same;
- and
- wherein one side of the stack of quantum wells is contacted with an ohmic contact and the opposite side of the stack of quantum wells is contacted with a rectifying junction.
6 more elements
A process for detecting electromagnetic energy whose photons have a first wavelength, comprising the steps of:
- connecting a semiconductor superlattice structure comprising a plurality of quantum wells which each have at least a first bound energy level and which are stacked upon one another and having a rectifying junction at one end of the stack and an ohmic contact at the other end of the stack in series with a current detector and with a voltage source, said voltage source being coupled to the current detector and the semiconductor superlattice structure through a polarity reversing switching network;
- directing electromagnetic radiation at the semiconductor superlattice structure;
- and
- repeatedly switching the polarity of the voltage source in order to fill up the first bound energy level of the plurality of quantum wells with electrons when a first polarity is applied to the semiconductor superlattice structure and in order to generate a current which is proportional to the number of quantum wells of the semiconductor superlattice structure and to radiation having a first wavelength when a second polarity of the voltage source is subsequently connected to the semiconductor superlattice structure.
1 more element
Dependencies are inferred from the claim text.