Fiber optical superconducting nanowire single photon detector (Technion)
- Summary
- Existing versions of superconducting nanowire single photon detectors are made on wafers made of silicon, sapphire, MgO or other materials. Light is directed to the detectors using an optical system which is built of several lenses or through a fiber which is mounted on a precision motor. These systems are expensive (tens of thousands of US dollars), as well as physically large and cumbersome. The detection efficiency of these systems is low (<25%) as most photons are not well directed to the detector or pass through it without being absorbed. In order to improve the efficiency, existing detectors are usually made larger than the minimum required, which results in a decrease in the maximal detection rate.This improved superconducting nanowire single photon detector consists of two parts: the superconducting nanowire and the optical cavity. The nanowire is a standard fiber connector upon which a thin layer of 5nm niobium-nitride (NbN) is deposited. Afterwards, a wire that is 100 nm wide and a few microns long is patterned in the NbN film with a focused ion beam. Finally, a standard coaxial cable is wire-bonded for electrical connectivity. The optical cavity is made of two highly reflective mirrors which serve to confine the light to increase the absorption probability by the sensor.
- Technology Benefits
- • The system is fabricated on the waveguide (optical fiber) naturally guiding the light to the detector and eliminating the need for additional costly guidance systems
• The system is easy to use, faster and less expensive to operate than conventional systems
• The fabrication price of a single system is estimated to be several USD.
• The amount of light impinging the detector is close to 100% since there are low losses in the fiber and each photon creates many “trails” to be absorbed in the detector.
• Since the detector is aligned to the light beam output in the fabrication step, a small detector can be fabricated, improving speed by few orders of magnitude.
- Technology Application
- • Quantum and deep space communications
• Astronomical, medical and other forms of academic research
- ID No.
- COM-1361
- Country/Region
- Israel
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