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Measurement of Single Photons - Build a Setup to Measure the Timing Accuracy of SNSPDs
Your goal is to build a setup in our laboratory which we can use to measure the timing accuracy of our SNSPDs. 20% Theory, 40% Measurement, 40% Programming.
Superconducting nanowire single-photon detectors (SNSPDs) are state-of-the-art single-photon detectors. They are operated at cryogenic temperatures of around 4 Kelvin and consist of a 5 nm thick and 100 nm wide superconductive nanowire. A single incident photon is then enough to break the superconductive state, leading to a detectable resistance change from zero ohm to about 1 kilo-ohm.
One outstanding property of SNSPDs is the ability to detect the time of incidence of a photon with an accuracy (also called jitter) of a few picoseconds, which is a key-enabler for many physics experiments. At IEF, we do research on further improving performance of high-speed SNSPDs. Yet, we currently lack a setup to measure the important timing accuracy of SNSPDs.
Superconducting nanowire single-photon detectors (SNSPDs) are state-of-the-art single-photon detectors. They are operated at cryogenic temperatures of around 4 Kelvin and consist of a 5 nm thick and 100 nm wide superconductive nanowire. A single incident photon is then enough to break the superconductive state, leading to a detectable resistance change from zero ohm to about 1 kilo-ohm. One outstanding property of SNSPDs is the ability to detect the time of incidence of a photon with an accuracy (also called jitter) of a few picoseconds, which is a key-enabler for many physics experiments. At IEF, we do research on further improving performance of high-speed SNSPDs. Yet, we currently lack a setup to measure the important timing accuracy of SNSPDs.
Your goal is to build a setup in our laboratory which we can use to measure the timing accuracy of our SNSPDs. In a first step, you will build and verify the setup at room-temperature without the SNSPD. This will involve programming to control all the measurement instruments. In a second step, you will modify the setup to work with our 4 Kelvin cryostat and characterize the jitter of previously fabricated SNSPDs.
This work will enable us to properly characterize our devices in the future, which is important for our research on single-photon detectors.
Your goal is to build a setup in our laboratory which we can use to measure the timing accuracy of our SNSPDs. In a first step, you will build and verify the setup at room-temperature without the SNSPD. This will involve programming to control all the measurement instruments. In a second step, you will modify the setup to work with our 4 Kelvin cryostat and characterize the jitter of previously fabricated SNSPDs. This work will enable us to properly characterize our devices in the future, which is important for our research on single-photon detectors.
a) Working principle of a SNSPD. A single photon creates a hot spot in the superconducting nanowire, thereby breaking its superconductive state. This leads to a change in resistance and thereby to a voltage pulse measurable with readout electronics. After a while, the detector recovers. Image from I. Esmaeil Zadeh et al., 2021.
b) SEM image of a fabricated SNSPD. The nanowire makes a meander to fill a large area, increasing the probability of photon absorption.
c) Principle of signal jitter: There is some fluctuation in the time between the photon hitting the nanowire and the voltage pulse measured in the readout electronics, leading to some timing uncertainty when exactly the photon was absorbed.
a) Working principle of a SNSPD. A single photon creates a hot spot in the superconducting nanowire, thereby breaking its superconductive state. This leads to a change in resistance and thereby to a voltage pulse measurable with readout electronics. After a while, the detector recovers. Image from I. Esmaeil Zadeh et al., 2021. b) SEM image of a fabricated SNSPD. The nanowire makes a meander to fill a large area, increasing the probability of photon absorption. c) Principle of signal jitter: There is some fluctuation in the time between the photon hitting the nanowire and the voltage pulse measured in the readout electronics, leading to some timing uncertainty when exactly the photon was absorbed.
Theory (20%)
Measurement (40%)
Programming (40%)
Theory (20%) Measurement (40%) Programming (40%)
Programming experience is mandatory. Prior experience in measuring electric circuits with an oscilloscope or similar instruments is beneficial, but not required. Fundamental knowledge of optics is desired (lecture “Optics & Photonics” or similar).
Programming experience is mandatory. Prior experience in measuring electric circuits with an oscilloscope or similar instruments is beneficial, but not required. Fundamental knowledge of optics is desired (lecture “Optics & Photonics” or similar).
ETH Zurich
Dominik Bisang, ETZ K 95
Prof. Dr. Jürg Leuthold, ETZ K 81
Gloriastrasse 35
8092 Zurich
Email: dbisang@ethz.ch
If you are interested in the thesis, just write a email and we can meet to discuss further details and answer your questions! :-)
ETH Zurich Dominik Bisang, ETZ K 95 Prof. Dr. Jürg Leuthold, ETZ K 81 Gloriastrasse 35 8092 Zurich
Email: dbisang@ethz.ch
If you are interested in the thesis, just write a email and we can meet to discuss further details and answer your questions! :-)