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Hamamatsu Streak Camera C5680 series PDF Print E-mail
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Written by Dirk Englund   
Friday, 14 September 2007

The C5680 is one of the most common streak cameras, and is pretty goodhttp://jp.hamamatsu.com/resources/products/sys/photo/150fibbun.jpg at most tasks.  When coupled to a spectrometer, it can resolve a spectrum with high spectral accuracy, approaching 2ps.  Even though it a 'common' tool, it still costs nearly $200k -- a pretty large investment.  But what are the alternatives, and how close do they come to the proven functionality of the Hamamatsu streak camera? 


First, a quick note about the operational principle of the streak camera. When a horizontal beam enters the streak camera, it is first imaged onto a cathode material which absorbs the photons and ejects electrons.  Unfortunately, despite decades of research, the materials for the cathode all have pretty bad conversion efficiency -- it's typically something like 1/1000 at best.  The electrons created in the cathode are then swept up and downward in sync with the repetition of theImage measurement (e.g., with the laser pulse repetition rate).  After this sweep, the electrons are multiplied up in a multi-channel-plate (like many multiplier tubes, where electrons hit the walls and knock of secondary electrons), where the gain is set through the device's software.  At the end of their short and promiscuous life, the electrons meet a harsh end when they slam into a phosphor screen.  The screen produces photons, which are then red by a CCD as the final image.  The whole process is shown in the figure on the right.  [updated: see also this new Java applet]

The major shortcomings of the streak camera are the low quantum efficiency and high price.  If you need to measure many wavelengths or spatial positions at once, then the streak camera's low conversion efficiency is in a way made up for by being massively parallel -- all wavelengths are read simultaneously. 

If the spectrum is not important, then a single photon counter module might be a good alternative.  It can be a lot cheaper -- about $5000 for a PerkinElmer SPCM, plus figure another $10-15k for electronics.  However, the time resolution will be about 50ps at best.  

 If you have plenty of optical signal (on the order of a mW), an autocorrelator is an alternative.  Here, the input beam is split into two, one is time delayed, and then they're re-combined on a nonlinear crystal, which measures the amount of overlap by second-harmonic generation.  The autocorrelator will cost about $10-20k (see e.g. Berkeley's Femtochrome (~$5-$10k), the German company APE (~$12-20k), or Newport PulseScount ($20+k -- rebranded APE??)).
 

So, if you need to measure several wavelengths at once, you need a streak camera. The Hamatsu series of streak camera are the best that money can buy and comes with great customer support.  Though Hamatsu is a Japanese company, it has offices and support based in the U.S. and Europe. The C5680 works reliably (no problem after 2 years).  The hardware is excellent, the software pretty good, with the major complaints being that data export could be simplified and that it shoudl be more crash-prone when selecting data regions on an active scan. Optronis is another manufacturer (based in Germany) that sells at lower price, but we did not test their models.  A third manufacturer is PhotonicsTech, based in Russia.  Their streak cameras sell for about 1/3 to 1/2 of the price of Hamamatsu, but again we do not know about the quality or support.  Alternatively, if you want to just measure one wavelength and have low signal, then an SPCM is an alternative if you can live with lower time resolution of 50ps instead of ~ 2ps.  Or, if you have ~1mW of power, an autocorrelator will work and provide time resolution down to 50fs. 

 

Further resources:

http://sales.hamamatsu.com/assets/pdf/hpspdf/C5680.pdf

http://www.optronis.com/content/view/15/40/ 

http://www.photonicstech.com/streak_cameras.htm 

 

 

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 Using this streak camera for measuring ultra-fast laser response:

Ultra-fast Photonic Crystal Nanolasers, Hatice Altug, Dirk Englund, and Jelena Vuckovic, Nature Physics , vol. 2, pp. 484-488 (July 2006)
Highlights: Also featured as the cover story in this issue of Nature Physics and highlighted in Nature Photonics and Laser Focus World.

2007.APL.Englund.efficient THz PC laser.pdf 2007.APL.Englund.efficient THz PC laser.pdf (305.67 KB) 

2007.APL.Englund.PC laser surface passivated.pdf 2007.APL.Englund.PC laser surface passivated.pdf (205.67 KB)






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