Abstract:
An avalanche diode arrangement (10) comprises an avalanche diode (11) that is coupled to a first voltage terminal (16) and to a first node (13), an event detector (14) for detecting a trigger event of the avalanche diode (11) and being coupled to the first node (13), a quenching circuit (15) that is coupled to the first node (13), and a detection circuit (20) coupled to the first node (13). The detection circuit (20) is configured to provide a detection signal (SVC2) that depends on a value of a node voltage (SVA) at the first node (13).
Abstract:
The present invention relates to a single photon detector (SPD) at telecom wavelength of 1.55 μm based on InGaAs/InP avalanche photodiode (APD). In order to operate the SPD at a low after-pulse noise, a DC bias voltage lower than the breakdown voltage is applied to an InGaAs/InP APD. A bipolar rectangular gating signal is superimposed with the DC bias voltage and applied to the APD so as to exceed the breakdown voltage during the gate-on time of each period of the gate signal. The use of the bipolar rectangular gating signal enabling us to operate the APD well below the breakdown voltage during the gate-off time, thereby make the release of the trapped charge carriers faster and then reduces the after-pulse noise. As a result, it permits to increase the repetition rate of the SPD.
Abstract:
An avalanche photodiode quenching circuit (20) incorporates an avalanche photodiode (APD) (22) and a first comparator (C1) responsive to reduction in APD voltage. The comparator (C1) is arranged to activate an APD quench circuit (38) in response to APD avalanche initiation. The circuit (20) also includes a second comparator (C2) arranged to reset the first comparator input (N2) in response to a further reduction in APD voltage caused by initiation of quenching. The second comparator (C2) is also connected to a monostable circuit (48) arranged to latch the first comparator output response to resetting. The monostable circuit (48) maintains the first comparator output level constant until the APD (22) has recharged.
Abstract:
A monitor for use in sample testing comprises a sample chamber for receiving a vessel containing a light-emitting substance, and an avalanche photodiode for receiving the emitted light and connected to a circuit for measuring the light received by the avalanche photodiode. The use of an avalanche photodiode enables the monitor to be portable and robust and to be included in a portable kit for carrying out hygiene monitoring in the field.
Abstract:
Es wird ein Lichtempfänger (22) mit einer Vielzahl von Lawinenphotodiodenelementen (24) angegeben, die jeweils mit einer Vorspannung oberhalb einer Durchbruchspannung vorgespannt und somit in einem Geiger-Modus betrieben sind, um bei Lichtempfang einen Geigerstrom auszulösen, wobei die Lawinenphotodiodenelemente (24) mehrere Gruppen (72 1 -72 n ) bilden. Dabei weist der Lichtempfänger (22) mehrere Vorspannungsanschlüsse (70a-c) mit unterschiedlichen Vorspannungen auf, um die Lawinenphotodiodenelemente (24) einer Gruppe (72 1 -72 n ) jeweils mit einer der unterschiedlichen Vorspannungen zu versorgen. Alternativ weist der Lichtempfänger (22) eine Vielzahl von Ausleseschaltungen (60, 62, 64) auf, die jeweils einer Gruppe (72 1 -72 n ) von Lawinenphotodiodenelementen (24) zugeordnet sind und die jeweils einen Messpfad (60) und einen Ausblendungspfad (64) sowie ein Schalterelement (62) aufweisen, um den Geigerstrom oder einen dem Geigerstrom entsprechenden Messstrom wahlweise dem Messpfad (60) oder dem Ausblendungspfad (64) zuzuführen.
Abstract:
Es wird ein Lichtempfänger (22) mit einer Vielzahl von Lawinenphotodiodenelementen (24) angegeben, die jeweils mit einer Vorspannung oberhalb einer Durchbruchspannung vorspannbar und somit in einem Geiger-Modus betreibbar sind, um bei Lichtempfang einen Geigerstrom auszulösen. Dabei weist der Lichtempfänger (22) mehrere Vorspannungsanschlüsse (40a-c) mit unterschiedlichen Vorspannungen auf, die Lawinenphotodiodenelemente (24) bilden mehrere Gruppen (42 1 -42 n ,), und die Lawinenphotodiodenelemente (24) einer Gruppe (42 1 -42 n ) sind jeweils mit einer der unterschiedlichen Vorspannungen versorgt.
Abstract:
The invention relates to a method for improving the dynamic range of a device for detecting light, preferably for use in a microscope, comprising at least two detection areas (8, 9), wherein the detection areas (8, 9) are each formed from an arrangement (array) (8, 9) of multiple single-photon avalanche diodes (SPAD), and wherein the detection areas (8, 9) each have at least one signal output (10, 11), wherein a characteristic curve (12, 13) is determined for each of the detection areas (8, 9), and wherein the characteristic curves (12, 13) are combined with one another and/or offset to obtain a correction curve (15) and/or a correction factor (17). The invention additionally relates to a device for detecting light, in particular for use in a microscope. Furthermore, the invention relates to a corresponding microscope.