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Image of Flex02-01D. The dimension of the external enclosure is approximately
3.25x2.5x0.8".
Functions:
Flex02-01D is a photon counting digital hardware that can be used as
- Single high resolution real time MT-64 multiple tau digital correlator (AxA or
AxB). Minimum sample time 1.5625ns. Option to record raw intensity series at a
user selectable sample time (0.1us or greater) simultaneously.
- Dual medium resolution MT-32 multiple tau digital correlator ({AxA, BxB}, or {AxB,
BxA}), . Minimum sample time 1.5625ns. Option to record raw intensity series at a
user selectable sample time (0.1us or greater) simultaneously..
- Quad standard resolution MT-16 multiple tau digital correlator {AxA, BxB, AxB,
BxA}. Minimum sample time 1.5625ns. Option to record raw intensity series at a user
selectable sample time (0.1us or greater) simultaneously..
- One channel photon history recorder. System clock speed: 60MHz.
- Dual channel photon history recorder. System clock speed: 60MHz.
In photon correlation mode, it calculates the correlation function(s) in real time
covering delay times from the 1.5625ns to about an hour.
In photon history recorder mode, it records the time between successive photon
events. This is measured by counting the number of ticks of the system clock between
the photon events. This time is then transferred to the host personal computer via
high speed Universal Serial Bus (USB). The amount of information to be transferred
is proportional to the count rate of the incoming photons. Using a lossless
compression technique, Flex02-12D transfers complete time series without gaps for average
count rate from 0 to approximately many megahertz.
Flex02-01D hardware specifications:
- Input signal: standard TTL pulses.
- Two BNC connectors
- One USB connector.
- Easy to use FlexWindows software and software for Windows98/2000/ME/XP libraries
included.
Correlation mode specifications:
1. Single MT-64 multiple tau channel layout ( sample time denoted at T, data width
W):
- Auto/cross correlations.
- 1.5625ns minimum sample.
- 1152 real time channels.
- Delay time range: 1.5625ns to 30 minutes in multiple tau channel layout.
- First 64 channels: T = 1.5625ns, W = 1 bits, delay times T to 64*T;
- Second 32 channels: T = 2*1.5625ns, W = 1 bits, delay times 66*T to 128*T
- Third 32 channels: T = 4*1.5625ns, W = 2 bits, delay times 66*T to 128*T;
- Fourth 32 channels: T = 8*1.5625ns, W = 3 bits, delay times 66*T to 128*T;
- Sample time doubles every 32 channels and data width increment 1 bit to prevent
overflow.
- The longest delay time is about 30 minutes.
2. Dual MT-32 multiple tau channel layout ( sample time denoted at T, data width
W):
- Auto/cross correlations.
- 1.5625 ns minimum sample.
- 608x2 real time channels.
- Delay time range: 1.5625ns to 30 minutes in multiple tau channel layout.
- First 32 channels: T = 1.5625ns, W = 1 bits, delay times T to 32*T;
- Second 16 channels: T = 2*1.5625ns, W = 1 bits, delay times 34*T to 64*T
- Third 16 channels: T = 4*1.5625ns, W = 2 bits, delay times 34*T to 64*T;
- Fourth 16 channels: T = 8*1.5625ns, W = 3 bits, delay times 34*T to 64*T;
- Sample time doubles every 16 channels and data width increment 1 bit to prevent
overflow.
- The longest delay time is about 30 minutes.
3. Quad multiple tau channel layout ( sample time denoted at T, data width W):
- Dual Auto and dual cross correlations.
- 1.5625 ns minimum sample.
- 288x4 real time channels.
- Delay time range:1.5625ns to 30 minutes in multiple tau channel layout.
- First 16 channels: T = 1.5625ns, W = 1 bits, delay times 0 to 16*T;
- Second 8 channels: T = 2*1.5625ns, W = 1 bits, delay times 9*T to 16*T
- Third 8 channels: T = 4*1.5625ns, W = 2 bits, delay times 9*T to 16*T;
- Fourth 8 channels: T = 8*1.5625ns, W = 3 bits, delay times 9*T to 16*T;
- Sample time doubles every 8 channels and data width increment 1 bit to prevent overflow.
- The longest delay time is about 30 minutes.
4. Linear mode ( sample time denoted at T, data width W):
- Single Auto or cross correlations.
- 50 ns minimum sample time, user adjustable.
- 1024 channels.
- 8 bit shift register width.
5. Single photon history recorder mode specifications:
- System clock: 60 MHz in one channel mode.
- 16.7 ns pulse pair resolution.
- Complete time series recorded on a PC hard drive for average count rate up to 10MHz or
more. The maximum count rate is somewhat host PC dependent.
6. Dual photon history recorder mode specifications:
- System clock: 60 MHz in two channel mode.
- 16.7 ns pulse pair resolution.
- Complete time series recorded on a PC hard drive for average count rate up to 10Mhz or
above. The maximum count rate is somewhat host PC dependent.
More about multiple tau theory.
Multiple tau theory was invented by Klaus Schätzel. The following papers discuss
the theory and the advantage of the multiple tau scheme.
- Klaus Schätzel. Single Photon Correlation Techniques. Dynamic Light
Scattering: The method and some applications, Edit by Wyn Brown, Clarendon Press, Oxford,
P 76, 1993.
- Klaus Schätzel et. Noise on Multiple-Tau Photon Correlation Data.
SPIE Vol. 1430, P109, Photon Correlation Spectroscopy: Multicomponent Systems,
1991.
- Klaus Schätzel. New Concept in Correlator Design. Inst. Phys. Conf. Ser. No.
77, P175, 1985.
- Klaus Schätzel et. Photon Correlation Measurements at Large Lag
Times. Journal of Modern Optics, Vol. 35, No. 4, P711, 1988.
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