Experimental study of a quantum random-number generator based on two independent lasers

Sun, Shi-Hai; Xu, Feihu

doi:10.1103/physreva.96.062314

Cited by 15 publications

(17 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, when no lasers are input, the electrical classical noise read by the detectors is normally distributed around 0 with a standard deviation of less than 7.5 mV. These values of signal and electrical noise are comparable in magnitude to those reported in [14]. With such values of photon numbers, high signal and low noise, it is possible to measure clean sinusoidal signals for the quadratures I and Q when they are sampled at rates on the order of GHz, as illustrated in Fig.…”

Section: Experimental Setup and Resultssupporting

confidence: 78%

“…Signals coming from the two lasers are sent to an optical hybrid (Kylia COH28) which provides the beam splitters and phase shifts that generate the two orthogonal quadrature readings of x (φ) with φ = 0, π/2. This optical hybrid reduces classical noise stemming from the fluctuation of the path lengths and phase shifters, being practically athermal, with phase variations of less than 17.5mrad for a change of ambient temperature of 90 • C. Therefore we can safely neglect phase variations due to the interferometers during the time of detection [14].…”

Section: Experimental Setup and Resultsmentioning

confidence: 99%

“…I and Q follow probability distributions which are correlated and complementary. Having an additional quadrature provides additional information on the value of the phase in the unit circle instead of just one projection onto the axis, which has been the customary technique for developing phase noise QRNGs which utilize randomness extraction [10,14,21]. With this additional information, it is possible to retrieve a distribution which can be made arbitrarily similar to a Uniform distribution stemming from spontaneous emission.…”

Section: Experimental Setup and Resultsmentioning

confidence: 99%

“…We use a second laser and measure the interference of the two laser sources with a pair of coherent detectors (for homodyne detection) that measure the phase variation directly. The method presented here builds up on works which have used the interference of two lasers to create RNGs [13][14][15], but the measurement of two orthogonal quadratures readily exposes the random behavior of the phase and requires a minimal amount of post-processing of the measured signal, since the probability distribution that obeys the random phase is uniform if samples are taken at intervals longer than the coherence time of the lasers.…”

Section: T Detmentioning

confidence: 99%

“…ξ (t) is a normally distributed phase with zero mean and a variance that becomes broader as time progresses [14]:…”

Section: Theorymentioning

confidence: 99%

See 4 more Smart Citations

Random number generation by coherent detection of quantum phase noise

Álvarez¹,

Sarmiento²,

Lázaro³

et al. 2020

Opt. Express

View full text Add to dashboard Cite

In 2010 Qi et al. [Opt. Lett. 35(3), 312 (2010)] demonstrated a random number generator based on the drift of the phase of a laser due to spontaneous emission, The out-of-the-lab implementation of this scheme presents two main drawbacks: it requires a long and highly unbalanced interferometer to generate a random phase with uniform probability distribution, or alternatively, a shorter and slightly unbalanced interferometer that notwithstanding requires active stabilization and does not generate a uniform probability distribution without randomness extraction. Here we demonstrate that making use of the random nature of the phase difference between two independent laser sources and two coherent detectors we can overcome these limitations. The two main advantages of the system demonstrated are: i) it generates a probability distribution of quantum origin which is intrinsically uniform and thus in principle needs no randomness extraction for obtaining a uniform distribution, and ii) the phase is measured with telecom equipment routinely used for high capacity coherent optical communications. The speed of random bit generation is determined by the photodetector bandwidth and the linewidth of the lasers. As a by-product of our method, we have obtained images of how phase noise develops with time in a laser. This provides a highly visual alternative way of measuring the coherence time of a laser.

show abstract

Section: Experimental Setup and Resultssupporting

confidence: 78%

Section: Experimental Setup and Resultsmentioning

confidence: 99%

Section: Experimental Setup and Resultsmentioning

confidence: 99%

Section: T Detmentioning

confidence: 99%

“…ξ (t) is a normally distributed phase with zero mean and a variance that becomes broader as time progresses [14]:…”

Section: Theorymentioning

confidence: 99%

See 3 more Smart Citations

Random number generation by coherent detection of quantum phase noise

Álvarez¹,

Sarmiento²,

Lázaro³

et al. 2020

Opt. Express

View full text Add to dashboard Cite

show abstract

Advanced Laser Technology for Quantum Communications (Tutorial Review)

et al. 2021

View full text Add to dashboard Cite

Quantum communications is the art of exchanging and manipulating information beyond the capabilities of our conventional technologies using the laws of quantum mechanics. With applications ranging from quantum computing to cryptographic systems with information-theoretic security, there is strong incentive to introduce quantum communications into many areas of our society. However, an important challenge is to develop viable technologies meeting the stringent requirements of low noise and high coherence for quantum state encoding, of high bit rate and low power for the integration with classical communication networks and of scalable and low-cost production for a practical wide-deployment. This tutorial presents recent advances in laser modulation technologies that have enabled the development of efficient and versatile light sources for quantum communications, with a particular focus on quantum key distribution (QKD). Such approaches have been successfully used to demonstrate several QKD protocols with state-of-the-art performance. The applications and experimental results are reviewed and interpreted in the light of a complete theoretical background, allowing the reader to model and simulate such sources.

show abstract

Practical source-independent quantum random number generation with detector efficiency mismatch

Wang

Wei

2020

Quantum Inf Process

View full text Add to dashboard Cite

Experimental study of a quantum random-number generator based on two independent lasers

Cited by 15 publications

References 30 publications

Random number generation by coherent detection of quantum phase noise

Random number generation by coherent detection of quantum phase noise

Advanced Laser Technology for Quantum Communications (Tutorial Review)

Practical source-independent quantum random number generation with detector efficiency mismatch

Contact Info

Product

Resources

About