In this study, a compact and low-power-consumption quantum random number generator (QRNG) based on a laser diode and a hybrid chip with integrated silicon photonics is proposed and verified experimentally. The hybrid chip’s size is 8.8 × 2.6 × 1 mm3, and the power of the entropy source is 80 mW. A common-mode rejection ratio greater than 40 dB was achieved using an optimized 1 × 2 multimode interferometer structure. A method for optimizing the quantum-to-classical noise ratio is presented. A quantum-to-classical noise ratio of approximately 9 dB was achieved when the photoelectron current is 1 μA using a balance homodyne detector with a high dark current GeSi photodiode. The proposed QRNG has the potential for use in scenarios of moderate MHz random number generation speed, with low power, small volume, and low cost prioritized.
In this study, a compact and low-power-consumption quantum random number generator (QRNG) based on a laser diode and a hybrid chip with integrated silicon photonics is proposed and verified experimentally. The hybrid chip’s size is 8.8 × 2.6 × 1 mm3, and the power of the entropy source is 80 mW. A common-mode rejection ratio greater than 40 dB was achieved using an optimized 1 × 2 multimode interferometer structure. A method for optimizing the quantum-to-classical noise ratio is presented. A quantum-to-classical noise ratio of approximately 9 dB was achieved when the photoelectron current is 1 μA using a balance homodyne detector with a high dark current GeSi photodiode. The proposed QRNG has the potential for use in scenarios of moderate MHz random number generation speed, with low power, small volume, and low cost prioritized.
In this study, a compact and low-power-consumption quantum random number generator (QRNG) based on a laser diode and silicon photonics integrated hybrid chip is proposed and verified experimentally. The hybrid chip's size is 8.8*2.6*1 mm3, and the power of entropy source is 80 mW. A common mode rejection ratio greater than 40 dB was achieved using an optimized 1*2 multimode interferometer structure. A method for optimizing the quantum-to-classical noise ratio is presented. A quantum-to-classical noise ratio of approximately 9 dB was achieved when the photoelectron current is 1 microampere using a balance homodyne detector with a high dark current GeSi photodiode. The proposed QRNG has the potential for use in scenarios of moderate MHz random number generation speed, with low power, small volume, and low cost prioritized.
The quantum random number generator (QRNG) operates based on fundamental quantum mechanical principles to produce high-quality random numbers. Recently, chip-based QRNGs have garnered significant attention due to their compact size, low cost, and reduced power consumption. In this work, we demonstrate a hybrid integrated QRNG leveraging continuous-wave (CW) laser phase fluctuations. Using advanced hybrid packaging techniques, we integrate a tunable, unbalanced Mach-Zehnder interferometer (uMZI), laser, and InGaAs photodiode (PD) within a 14-pin butterfly package. To enhance the long-term stability and reliability of the QRNG, a negative temperature coefficient (NTC) thermistor is also attached to the chip for thermal regulation. The resulting integrated QRNG has a footprint of just 30 mm × 12.7 mm, and delivers a random number generation rate of 4.68 Gbps after min-entropy evaluation and post-processing. The combination of compact size and high-speed performance makes this hybrid integrated QRNG ideal for high-speed, large-scale applications.
Recent advancements in integrated photonics have shown great promise for the serial production of chip-scale quantum random number generators (QRNG). Considerable progress has been made towards developing fully on-chip QRNGs that exploit the interference of phase-randomized fields from two independent lasers. While a common alternative design, based on a single laser and interferometer, would further improve power consumption and ease of operation, monolithic integration of such a design has thus far faced challenges, including high losses and crosstalk. We solve these key challenges and report fast single-laser interferometric QRNGs integrated onto monolithic chips. By combining on-chip optical amplification with electronic common-mode rejection techniques, our photonic integrated circuits (PICs) stably convert the spontaneous emission phase noise of a diode laser into electronic pulses of high-contrast random intensity at GHz clock rates. Using real-time, hash-function-based randomness extraction, uniformly distributed, truly unpredictable random numbers are generated at a rate of 3 Gbps.
Quantum random number generators play a crucial role in securing high-demand information contexts by producing true random numbers. Nevertheless, the large volume and high cost limit their widespread use. Here, we propose a system on-chip that fully leverages the advantages of different photonic integrated platforms, where the interference optical paths and photodiodes are integrated on a standard silicon process, while the laser source on-chip is realized on a III–V platform. Using micro-lens coupling package technology, which contributes to a topnotch coupling loss lower than 2 dB, the components on different platforms are combined and packaged with the amplifier circuits in a 42 mm × 24 mm footprint in a butterfly form. This complete miniaturized and cost-effective entropy source enables outputting a vacuum noise signal with a 3-dB bandwidth of over 500 MHz. After sampling and post-processing, a random number generation rate of up to 6.57 Gbps is achieved. The results show a feasible way of overcoming the laser integration problem with silicon-based integrated quantum photonics. Foreseeable, commercial applications on a large scale are substantially promoted.
Random numbers find applications in a range of different fields, from quantum key distribution and classical cryptography to fundamental science.They also find extensive use in gambling and lotteries.By exploiting the probabilistic nature of Quantum Mechanics, quantum random number generators (QRNGs) provide a secure and efficient means to produce random numbers.Most of the quantum random number generators demonstrated so far have been built in bulk optics, either using free space or fibre-optic components.While showing good performance, most of these demonstrations are strongly limited in real life applications, due to issues such as size, costs and the manufacturing process.In this thesis I report the demonstration of three different QRNGs based on integrated photonics.First, I demonstrated a QRNG based on homodyne measurement of optical vacuum states on a Silicon-on-insulator (SOI) chip.Second, I developed a SOI QRNG based on phase fluctuations from a laser diode.In these two schemes all the optical and opto-electronic components, excluding the laser, were integrated onto a silicon-on-insulator device.These schemes, being built on a silicon-on-insulator chip are potentially CMOS compatible and pave the way for being integrated onto other more complex systems.These QRNGs showed Gbps generation rates and passed the statistical tests provided by NIST.Third, I report the preliminary study of a QRNG based on homodyne measurement of optical vacuum states onto a Indium Phosphide (InP) chip.In this third experiment, all the components, including a laser diode, were monolithically integrated in the same chip, which provide a great advantage in terms of the overall size of the optics of the device.First, I would like to thank Jonathan, for the opportunity to pursue my PhD and for guiding my research in these four years.Thank you for giving me the chance to follow my curiosity and for pushing me to get the best out of my research.Thank you, Dylan, for being so helpful, always ready to answer my questions.I would like to thank Giacomo for sharing a big part of my research in these years
Real-time high-speed mutually independent two-channel quantum random number generator (QRNG) device has been proposed using a programmable photonic integrated circuit in silicon photonics platform. Broadband random fluctuations of quantum photonic waveguide vacuum mode is harnessed in each of the mutually independent channels by mixing a guided coherent laser light operating at λ ∼ 1550 nm. All classical noises arising out of electrical, mechanical, thermal disturbances, etc. are minimized by the use of homodyne detection and appropriate programming of the photonic integrated circuit. The method of classical noise elimination has been supported with an appropriate theoretical modeling and experimental observations. The raw random number generation rate per channel was 4 Gbps, when the output signal from the homodyne detectors (bandwidth 1.6 GHz) was sampled at 500 MSa/s and subsequently digitized by a 14-bit analog-to-digital converter. We have also shown that the proposed PPIC design can be scaled up to higher number of channels using CMOS fabrication process compatible silicon photonics technology. Such mutually independent multi-channel QRNG sources are especially useful for high-speed chip-scale quantum key distribution (QKD) transceivers.