Infrared and far infrared detector or amplifier using mos structure element

Claim 2

A solid-state electronic device according to claim 1, wherein the semiconductor layer of said MOS element is made of such a material as to be transparent to the predetermined wavelength range of said radiation beam, said radiation beam is directed to the surface of said semiconductor layer opposite to the insulating layer.

Claim 3

A solid-state electronic device according to claim 1, wherein the semiconductor layer of said element is made of a material selected from the group consisting of InSb, In As, GaSb and GaAs.

Claim 4

A solid-state electronic device according to claim 1, wherein said device further comprises an optical chopper disposed at the entrance of said optical path means for periodically interrupting said radiation beam, and said electric circuit includes a lock-in amplifier synchronized with said optical chopper, whereby said radiation beam is detected with low noise.

Claim 5

A solid-state electronic device according to claim 5, wherein said channel current is set, when no radiation is present, a little below the value at which said channel current changes abruptly with an increase in the source-drain voltage of said element to which a given gate voltage is applied.

Claim 6

A solid-state electronic device according to claim 6, wherein said voltage source is adapted to supply periodically scanning gate voltage to said element, and said circuit for measuring said channel current includes a differentiating circuit, whereby a sharp pulsive response is obtained to said radiation beam.

Claim 7

A solid-state spectrometer for the wavelength range from infrared to far infrared, comprising: a MOS element being responsive to a gate voltage to produce an inversion layer therein; means for cooling said element to such a low temperature that most carriers in said inversion layer populate in the ground quantum level formed therein, said cooling means being equipped with optical path means to direct a radiation beam to said inversion layer; a voltage source for applying a scanning gate voltage to said element to scan the energy difference between said ground level and an excited quantum level formed in said inversion layer, said energy difference being equivalent to the absorption edge in said inversion layer due to the electronic transition between said levels; electrical means for setting the source-drain voltage of said element at such a small value that no said carriers are excited by the field energization of said set voltage, said radiation beam raising said carriers from said ground level to said excited level to convert them into a channel current to flow through said inversion layer; a first electric circuit for computing, amplifying and differentiating said channel current in synchronization with said gate voltage to correct the dependency of the photosensitivity of said element on said gate voltage and to separate the integrated wavelength component; and means for displaying the output signal from said first electric circuit.

Claim 8

A solid-state spectrometer according to claim 8, wherein said spectrometer comprises a second electric circuit for transforming said gate voltage into a predetermined waveform connected with said voltage source, and said displaying means is an oscilloscope, the signal terminal thereof being connected with the output of said first electric circuit, the scanning terminal thereof being connected with the output of said second electric circuit, whereby the intensity distribution of the wavelength components of said radiation beam is displayed directly on the face of the cathode-ray tube of said oscilloscope.

Claim 9

A solid-state radiation amplifier for the wavelength range from infrared to far infrared comprising: a MOS element being responsive to a gate voltage to produce an inversion layer therein; means for cooling said element to such a low temperature that most carriers in saiD inversion layer populate in the ground quantum level formed therein, said cooling means being equipped with first optical path means to direct a radiation beam to said inversion layer and with second optical path means to direct a radiation beam emitted from said inversion layer outward; a voltage source for applying a variable gauge voltage to said element to control the energy difference between said ground level and an excited quantum level formed in said inversion layer; and means for setting a source-drain voltage at such a value that the electronic transition by the field energization of said voltage produces the population inversion of said carriers, whereby the component of said radiation beam having a wavelength equivalent to said energy difference is amplified by the stimulated emission.