Shanni presented on “Construction of an Entangled Photon Source for Experimenting with Quantum Technologies” at the 2015 Hackaday SuperConference.
Her lecture has been uploaded by Hackaday and is available now available online. CLICK HERE for the link to the HaD Blog and Video.
I HAVE NO RELATION TO SELLER – Just passing along in case someone is interested.
eBay item number 271206242864:
“The EG&G (or Perkin Elmer) SPCM-AQR is a self-contained module which detects single photons of light over the wavelength range from 400 nm to 1060 nm and sensitivity which often outperforms PMTs. The option 13-FC indicates 180 micron diameter Si APD, Dark Count < 250cps and FC connector attached.
I obtained this detector in working order five years ago and have not used it since then. The detector comes with two unknown optical fiber cables (one end: FC, the other end: bare fiber) and a supply cable to which you need to give 5V. No manual included. The US sale only.”
From “Loophole-free Einstein–Podolsky–Rosen experiment via quantum steering”, New Journal of Physics, Volume 14, May 2012
A very interesting article by Bernhard Wittmann, Sven Ramelow, Fabian Steinlechner, Nathan K Langford, Nicolas Brunner, Howard M Wiseman, Rupert Ursin,and Anton Zeilinger, entitled “Loophole-free Einstein–Podolsky–Rosen experiment via quantum steering” appeared in the Nature’s New Journal of Physics, Volume 14, May 2012.
This paper describes a Bell’s Inequality Violation experiment in which the “fair sampling” loophole has been closed. This loophole posits the possibility that classical – rather than quantum – effects could be responsible for measured correlations between entangled pairs of photons in a Bell’s Inequality Violation experiment. The paper’s abstract reads:
“Tests of the predictions of quantum mechanics for entangled systems have provided increasing evidence against local realistic theories. However, there remains the crucial challenge of simultaneously closing all major loopholes—the locality, freedom-of-choice and detection loopholes—in a single experiment. An important sub-class of local realistic theories can be tested with the concept of ‘steering’. The term ‘steering’ was introduced by Schrödinger in 1935 for the fact that entanglement would seem to allow an experimenter to remotely steer the state of a distant system as in the Einstein–Podolsky–Rosen (EPR) argument. Einstein called this ‘spooky action at a distance’. EPR-steering has recently been rigorously formulated as a quantum information task opening it up to new experimental tests. Here, we present the first loophole-free demonstration of EPR-steering by violating three-setting quadratic steering inequality, tested with polarization-entangled photons shared between two distant laboratories. Our experiment demonstrates this effect while simultaneously closing all loopholes: both the locality loophole and a specific form of the freedom-of-choice loophole are closed by having a large separation of the parties and using fast quantum random number generators, and the fair-sampling loophole is closed by having high overall detection efficiency. Thereby, we exclude—for the first time loophole-free—an important class of local realistic theories considered by EPR. Besides its foundational importance, loophole-free steering also allows the distribution of quantum entanglement secure event in the presence of an untrusted party.”
A recent paper entitled “Displacing entanglement back and forth between the micro and macro domains” discusses the experimental possibility of displacing quantum entanglement into the domain where it involves two macroscopically distinct states, i.e. two states characterized by a large enough number of photons. Specifically, the authors describe the process by which they start with two entangled spatially separated optical modes at the single photon level and subsequently displace one of these modes up to almost a thousand photons.
With so many photons, it would be possible, at least in principle, to see entangled photon pulses with our eyes. This would also make it possible to perform entanglement experiments with linear coarse-grain detectors (NOT single-photon detectors).
Mathieu Stephan, a high speed electronics engineer at the Swiss quantum information systems company id Quantique SA (and prolific hardware hacker) designed the very fast pulse amplifiers needed to acquire signals from avalanche photodiodes for this experiment. He has posted a thorough description of his design on his blog: http://www.limpkin.fr.
Prof. Mark Beck from the Dept. of Physics at Whitman College recently published an excellent book titled “Quantum Mechanics: Theory and Experiment.” It is written for an advanced undergraduate/graduate quantum mechanics class. This book presents the theory in its full formalism (with thorough, high-level math), as well as describes five laboratory experiments that explore the use of entangled photons in the undergraduate lab.
Prof. Beck’s laboratory experiments use the same type of system as we describe in Chapter 8 of Exploring Quantum Physics Through Hands-On Projects, so if you are up to the math, we heartily recommend this book to continue your exploration with your entangled-photon system.
Today I found two Perkin Elmer SPCM-AQE-13-FC SPCMs for sale on eBay at $400 each. eBay auction numbers are 280877451350 and 280877453169. I am passing along this information in case that blog readers may be interested. I have no connection whatsoever to seller.
Someone (I don’t know the seller) is selling brand new Perkin Elmer C30902E Silicon Avalanche Photodiodes on eBay. Auction number: 200747161278.
These are NOT chilled by a thermoelectric cooler, so their internal noise may be too large for experiments with entangled photons unless you rig some sort of external Peltier element to keep them chilled. However, if you are developing a SPCM, using $91 SPADs during debugging is a lot better than frying $1,000 TE-cooled SPADs.
I. Rech, I. Labanca, M. Ghioni, and S. Cova of the Politecnico di Milano in Italy described an interesting modification to the Perkin Elmer SPCM-AQR Single-Photon Counting Module (SPCM) to improve its timing characteristics in:
I. Rech, I. Labanca, M. Ghioni, and S. Cova, “Modified single photon counting modules for optimal timing performance“, Rev. Sci. Instrum. 77, 033104 (2006); doi:10.1063/1.2183299 (5 pages). Continue reading
Figure 144 in the book shows the schematic diagram for our d.i.y. thermoelectrically cooled single-photon avalanche photodiode (SPAD). Our design calls for a ThermOptics DN1225 TEC controller. However, this model is not available any more. Fortunatelly, the ThermOptics’ DN1221 subminiature Bipolar Temperature Controller for Thermoelectric Coolers (TEC) is equally suitable by adapting the pinout and adjusting component values. Continue reading
Image Credit: Excelitas Technologies
Figure 144 in the book shows the schematic diagram for our d.i.y. passively-quenched SPCM based on a Perkin-Elmer C30902S-DTC SPAD.
In our circuit, the SPAD is reverse-biased through a 200kΩ resistor. This value is sufficiently large that an avalanche in the SPAD will be quenched by itself within less than a nanosecond. The pulses produced by the SPAD are AC-coupled to a fast constant-level discriminator which has an output that is compatible with TTL logic circuits. Continue reading
ALPhA (Advanced Laboratory Physics Association) has worked out a deal with Excelitas to sell Single-Photon Counting Modules (SPCMs) to instructional labs. The detectors carry labels specifying that these units belong in the undergraduate instructional labs and not in research labs. These educational detectors have reduced specs, notably a higher background dark count rate, compared to other models from the company.
The set of four SPCMs can be purchased for $5,720 (instead of the usual ~$10k). Continue reading
Image Credit: Oliver Jan and Phil Makotyn
In 2006, then-students Oliver Jan and Phil Makotyn from University of Illinois (at Professor Paul Kwiat’s lab) developed an actively-quenched Single-Photon Counting Module (SPCM) based on the Perkin-Elmer C30902S-DTC Single-Photon Avalanche Photodiode (SPAD). Continue reading
