After many years of use, the image intensifier tube (IIT) in the image intensifier system that I use for my experiments in quantum physics developed some nasty half-moon shadows in the periphery, so I decided to rebuild it with another MX-10160-type IIT. I documented the build in the following document: diy Image Intensifier System Prutchi
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.”
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.
The nice guys at the Yahoo GammaSpectrometry Group developed multichannel analyzer software for the $79 SainSmart DSO201 Pocket-Sized Digital Oscilloscope. The upload of the MCA software to the oscilloscope is really easy (via USB), and it allows the PMT probe shown in the book’s Figure 30 to be connected directly to the oscilloscope’s input with no need for a PMT amplifier!
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.
We built the bulk of our PMT amplifier/processor/discriminator on a Universal PDIP Operational Amplifier Evaluation Module by Texas Instruments (model OPAMPEVM-PDIP). Click on the picture above for a full-size version of the picture.
The diagram in the following pdf file shows the connection layout for the circuit shown in the book’s Figure 34: PMT Processor PCB Continue reading
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
In Chapter 5 of the book we list a short Matlab® program to integrate successive video frames from our diy intensified camera to image double-slit interference patterns obtained by shooting a single photon at a time.
The program listed in the book uses Vision for Matlab (VFM). However, this utility is not compatible with all versions of Windows and Matlab. An alternative is VCAPG2 by Kazuyuki Kobayashi available at http://www.ikko.k.hosei.ac.jp/~matlab/matkatuyo/vcapg2.htm (Also available from our SOFTWARE page). 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
Our diy entangled-photon source, shown in the book’s Figure 142, uses two BBO crystals that support type I down-conversion that are mounted according to a design by Paul Kwiat and his colleagues at the Los Alamos National Laboratory.
The nonlinear crystal in our photon entangler comprises two 5 mm x 5 mm x 0.1 mm BBO crystals mounted face-to-face at an angle of 90 degrees to each other. As shown in the book’s Figure 140, pump photons polarized at 45 degrees produce two cones of entangled down-converted photons.
This is the 405 nm pump laser used in the circuit shown in the book’s Figure 141. The laser is built from a Blu Ray disk burner laser diode. We drive the laser diode with 160 mA to produce around 100 mW of 405-nm polarized light. The laser diode is capable of producing 250 mW, but we prefer to drive it much more conservatively. Continue reading
Figure 34 in the book shows the schematic diagram for the photomultiplier tube (PMT) signal processing circuit that amplifies the narrow pulses detected by the PMT probe. The discriminator stage removes small pulses produced by thermal noise in the tube. A pulse stretcher outputs pulses that can be heard on a speaker. In addition, the analog output is suitable for use with a sound-card-based multichannel pulse-height analyzer (MCA). Continue reading
The book’s Figure 32 shows the schematic diagram for a low-cost, variable-voltage PMT power supply based on a BXA-12579 inverter module that is originally designed as a power supply for cold-cathode fluorescent lamps. This under-$20 module produces 1,500VAC at around 30kHz from a 12VDC input.
We are posting this picture to help you build your own power supply. It shows the BXA-12579 that has been modified as described in the book. The op-amp to the right of the CCFL module is used to control the voltage supplied to the module. The high-voltage AC output of the inverter is rectified and doubled and filtered by the diodes and capacitors at the left of the CCFL module. Continue reading
