We report on a multispectral superconducting nanowire single-photon detector based on a thickness-modulated optical film stack. This unique optical film structure provides a modulated reflection bands used for single-photon detection in well-separated multiple wavelength ranges. The fabricated detector shows four detection bands with the system detection efficiencies of 76.2%, 76.9%, 81.3%, and 85.0% at the wavelengths of 505, 610, 1030, and 1550 nm, respectively. A 4-pixel multispectral detector array is then demonstrated, and a photon flux reconstruction experiment is performed to reconstruct the photon flux at the wavelengths of interest. The present multispectral detector enriches the available optical architectures and may have interesting multispectral applications such as multispectral ranging or imaging.
We report on a multispectral superconducting nanowire single-photon detector based on a thickness-modulated optical film stack. This unique optical film structure provides a modulated reflection bands used for single-photon detection in well-separated multiple wavelength ranges. The fabricated detector shows four detection bands with the system detection efficiencies of 76.2%, 76.9%, 81.3%, and 85.0% at the wavelengths of 505, 610, 1030, and 1550 nm, respectively. A 4-pixel multispectral detector array is then demonstrated, and a photon flux reconstruction experiment is performed to reconstruct the photon flux at the wavelengths of interest. The present multispectral detector enriches the available optical architectures and may have interesting multispectral applications such as multispectral ranging or imaging.
In this work, we report multispectral superconducting nanowire single photon detectors (SNSPDs) that can simultaneously detect single photons at multiple wavelengths with high efficiency. The superconducting nanowires are fabricated on an all-dielectric mirror consisting of two quarter-wave stack reflectors with separated central wavelengths. The unique optical structure results in serially coupled optical cavities, leading to multiple resonant absorption bands that are utilized for high-efficiency single photon detection. The fabricated detector shows system detection efficiencies of >80% at the three target wavelengths of 1550 nm, 1310 nm, and 1064 nm. The multispectral detector may eliminate the need for multiple SNSPDs for different wavelengths in a system, potentially resulting in a reduction in size, weight, and power, as well as in the cost of the overall detection system. The detector may also find interesting use for applications such as multispectral ranging or imaging.
Abstract The multispectral and polarization-sensitive detection of superconducting nanowire single photon detectors (SNSPDs) have been identified in applications, such as quantum information processing and polarimetric imaging systems. Distributed Bragg reflectors (DBRs) demonstrate exceptional wavelength-selective reflectivity, and subwavelength gratings (SWGs) exhibit the ability to separate different polarized light. In this paper, a multispectral and polarization-sensitive SNSPD design is proposed by combining DBRs and SWGs. In the design, the NbN nanowires are positioned on two DBR stacks with respective central wavelengths of 1400 nm and 930 nm, followed by integration of Si-Al composite gratings onto the surface layer. Numerical simulation results show that, setting the fill factor at 0.5, the polarization sensitivity of the SNSPD is ∼0.98, with absorption efficiencies of ∼95%, ∼92%, and ∼94% at wavelengths of 1064 nm, 1310 nm, and 1550 nm, respectively. The design proposed in this work could facilitate the development of high-performance SNSPDs, potentially advancing their applications in multispectral polarization imaging and quantum communication systems.
This Superconducting nanowire single-photon detectors (SNSPDs) are efficient devices that absorb and convert incident photons to discriminable signals. However, the multi-spectral response of it is limited due to the resonance of the traditional optical cavity. In this work, we present a multi-spectral SNSPD that can detect single photon at multiple wavelengths with high efficiency simultaneously. The stack structure consists of nanowires embedded in the high refractive index dielectric strips, spacer layers and the reflection layer. The designed detector shows absorption efficiencies of over 85% at the three target wavelengths of 1550 nm, 1310 nm and 1064 nm while the filling factor of nanowire is only 20%. Meanwhile, the reset time is dramatically reduced by applying the low-filling-factor nanowire. Such ultrafast, high-performance single-photon detectors are promising for the rapidly advancing fields of multi-spectral imaging, satellite laser ranging and quantum communications.
In this work, we report a large-active-area multispectral superconducting nanowire single-photon detector for free-space applications. The detector is realized by fabricating NbTiN nanowire with an active area of 35 µm diameter on two serially connected dielectric mirrors that can simultaneously and efficiently detect single photons at the three typical wavelengths employed in free-space applications, namely, 532, 850, and 1064 nm. Maximal system detection efficiencies (SDEs) of 80.0% at 532 nm and 850 nm and 75.8% at 1064 nm are achieved for polarized light obtained by coupling the detector with an SMF-28 fiber. Upon coupling with a 50 µm multimode fiber, SDEs of 68.6%, 59.6%, and 47.0%, are achieved for 532, 850, and 1064 nm wavelength unpolarized light, respectively. Moreover, the detector shows timing jitters of 37.1 and 41.0 ps when coupled with SMF-28 fiber and 50 µm multimode fiber. This type of detector with a large active area and multiwavelength detection capability is promising for both single and multiwavelength free-space applications.
We propose a superconducting nanowire single photon detector (SNSPD) that can work efficiently at two target wavelengths and has a significant improvement in the counting rate due to the low-filling-factor nanowires in the silicon slots and the silver reflector. Numerical simulations show that the absorption efficiency can be over 90% at a single wavelength, whether the incident light wavelength is 1550 nm or 1064 nm, and over 80% when the SNSPD is designed to work at both wavelengths. In addition, the reset time is about 24% of the conventional SNSPDs. Our work presents a design for fabricating faster, larger-area, and multispectral SNSPDs with a high efficiency, which can be applied in applications such as quantum optics communication and multiwavelength sensing.
High-efficiency superconducting nanowire single-photon detectors (SNSPDs), which have numerous applications in quantum information systems, function by using the optical cavity and the ultrasensitive photon response of their ultra-thin superconducting nanowires. However, the wideband response of superconducting nanowires is limited due to the resonance of the traditional optical cavity. Here, we report on a supercontinuum SNSPD that can efficiently detect single photons over an ultra-broad spectral range from visible to mid-infrared light. Our detection approach relies on using multiple cavities with well-separated absorbed resonances formed by fabricating multilayer superconducting nanowires on metallic mirrors with silica acting as spacer layers. Thus, we are able to extend the absorption spectral bandwidth while maintaining considerable efficiency, as opposed to a conventional single-layer SNSPD. Our calculations show that the proposed supercontinuum SNSPD exhibits an extended absorption bandwidth with increased nanowire layers. Its absorption efficiency is greater than 70% over the entire range from 400 to 2500 nm (or 400 to 3000 nm), when using two-layer (or three-layer) nanowires. As a proof of principle, the SNSPD with bilayer nanowires is fabricated based on the proposed detector architecture with simplified geometrical parameters. The detector achieves broadband detection efficiency over 60% from 950 to 1650 nm. This type of detector may replace multiple narrow band detectors in a system and find uses in the emerging and rapidly advancing field of atomic and molecular broadband spectroscopy.