Thomson-csf

Bernard Munier

Marc Arques

Paul De Groot

Yves Henry

Claude Weisbuch

Philippe Defranould

Guy Moiroud

Claude Weibuch

Michel Moulin

A photocathode having internal amplification includes a first electrode adapted for receiving a first voltage, and for transmitting received photons. An absorption layer is disposed adjacent the first electrode and comprises a P-type semiconductor material having a forbidden band of sufficiently small width to cause photons received through said first electrode to be converted into electron-hole pairs. At least one ionization-induced electron multiplication layer is disposed adjacent the absorption layer. Each such multiplication layer comprises two layers of N-type semiconductor material having respectively two different compositions at an interface therebetween. The two different compositions at the interface cause the multiplication layer, when biased, to accelerate the electrons received from the absorption layer to a degree greater than the acceleration provided to the holes received from the absorption layer. A second electrode is disposed adjacent the multiplication layer and receives a second voltage to cause the photocathode to be biased. In addition, the second electrode transmits the accelerated electrons received from the multiplication layer. An emission layer is disposed adjacent the second electrode and comprises a material which produces negative electron affinity to cause the accelerated electrons received from the second electrode to be emitted into a vacuum.

Photocathode having internal amplification

The device for detection with time delay and phase integration comprises detectors arranged in rows and columns. Capacitors for storing electric charges are associated with each detector. Any one point of the image is received sequentially by the detectors of a given row and each column of detectors is addressed sequentially by a shift register. The data stored by the detectors of a given row are received sequentially on a common lead by a charge-coupled device associated with each row. The function of this device is to delay the data delivered by the detectors of the same row in order to add these data in synchronism. The charge-coupled devices are located externally with respect to the rows of detectors. Their outputs are connected as feedback to their inputs in order to re-inject into the device the information previously received from a detector in phase with the information received from the following detector of the same row.

Device for detection with time delay and phase integration

In one example of construction, a high-performance photocathode has the following structure:

High-performance photocathode

In a device photosensitive to infra-red radiation each infra-red detector is associated with means enabling the injection into a semiconductor substrate of a quantity of charges representing a function of the infra-red radiation received by the detector, and with means assuring the storage of these charges. The storage means of the detectors of one and the same line are joined via connections to charge reading means, common to the detectors of one and the same line, and which assure the column after column reading of the detectors by reason of a shift register which successively addresses the storage means of the detectors of one and the same column. The device as a whole may be integrated within a cryostat having a single high-level output.

Device photosensitive to infra-red radiation

A photosensitive device for the infrared range wherein each detector is connected to a first and a second MOS transistor. The second MOS transistors are addressed, column by column, by a first shift register. The first MOS transistors are connected, line by line, to a charge storage capacity and to a third charge reading MOS transistor addressed by a second shift register. The whole of the device is placed in a cryostat which only has a single output.

Photosensitive device for the infrared range

In a device comprising N lines and M columns of infrared-sensitive photodiodes, the charges derived from the detectors of one column are integrated in a first series of capacitors. MOS transistors connect the first series of capacitors to a second series in order to produce a distribution of charges between these capacitors. MOS transistors mounted as emitter-followers read the level of charges within the second capacitors while integration of the charges takes place in the first capacitors of the detectors of the next column. The detectors and the remainder of the device are integrated on two different semiconductor substrates but the device as a whole is integrated in one cryostat having a single output.

Photosensitive device for infrared radiation

A device for the line-by-line electrical analysis of an image. It comprises a piezo-electric medium associated with a semiconductor medium scanned by the interaction of two elastic waves propagated at the surface of the piezoelectric medium, and an electrode network. The electrodes are disposed on the semiconductor medium parallel to the scanning direction and each of which supplies an electrical signal the amplitude of which characterizes the luminous intensity of the elementary zones of the image.

Electro-acoustic device for reading a two dimensional image by means of

A device for the electrical line-by-line analysis of an optical image in two dimensions. It comprises a piezoelectric medium associated with a semiconductive medium onto which the image is projected, and at least three transducers emitting surface elastic waves on the piezoelectric medium. Two of three transducers emit pulses in two separate directions, the convergence point of which constitutes a reading point of the image. This point moves as a function of time along a straight line which constitutes an analysis line of said image. The third transducer emits a long wave, the wave vector of which is such that the wave vector resulting from the interaction of the three waves is zero.

Electroacoustic device for reading an optical image in two dimensions

A reading device for analysing an optical image in one dimension and for converting it into an electrical signal the amplitude of which characterizes the light intensity of the elemental zones analysed by a semiconductive substrate and scanned by the interaction of acoustic surface waves on a piezoelectric substrate, which comprises, for increasing its sensitivity, discrete junctions on the surface of the photosensitive semiconductive substrate 'scanned' by the surface waves arising out of the non-linear interaction, and wherein the output signal is collected between an electrode disposed on the other surface of the semiconductive substrate and an electrode of the piezoelectric substrate.

Growing community of inventors

Seyssinet-Pariset, France

Bernard Munier