Fusion instruments APDCAM-10G User manual

APDCAM-10G User’s Guide
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APDCAM-10G
Digital Avalanche Photodiode camera
with 10 Gbit digital interface
User’s Guide
Version 1.13
Date: 16 March, 2017
FUSION Instruments Kft.
Budapest, Hungary
www.fusioninstruments.com
[e-mail]
Copyright © Fusion Instruments Kft. 2014-2017

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CONTENTS
1. Using this document ................................................................................................... 3
2. Overview..................................................................................................................... 4
2.1. The APDCAM family.......................................................................................... 4
2.2. Overview of APDCAM-10G ............................................................................... 4
3. System components .................................................................................................... 7
4. Using APDCAM....................................................................................................... 10
4.1. Operating environment....................................................................................... 10
4.2. Power connection............................................................................................... 10
4.3. Camera cooling .................................................................................................. 10
4.4. PC communication............................................................................................. 11
4.5. Mechanical interface.......................................................................................... 12
4.6. Software interface .............................................................................................. 12
4.7. Optical input interface........................................................................................ 12
4.8. The detector and its operation............................................................................ 13
4.9. Data acquisition.................................................................................................. 13
5. APDCAM-10G Reference Manual.......................................................................... 15
5.1. System Overview ............................................................................................... 15
5.2. Detector and analog electronics ......................................................................... 16
5.3. Communication to the host PC........................................................................... 18
5.4. Data Acquisition................................................................................................. 19
5.4.1. Clock and sample........................................................................................ 20
5.4.2. Trigger......................................................................................................... 20
5.4.3. Digital filter and bit resolution reduction.................................................... 21
5.4.4. Offset control .............................................................................................. 23
5.5. Control unit ........................................................................................................ 24
5.5.1. Detector bias voltage setting....................................................................... 24
5.5.2. Detector temperature control ...................................................................... 24
5.5.3. Shutter and calibration light........................................................................ 25
5.6. 10Gbit communication and timing unit ............................................................. 25
5.6.1. Host communication................................................................................... 25
5.6.2. Data output.................................................................................................. 27
6. Troubleshooting........................................................................................................ 29
7. Order options ............................................................................................................ 30
Appendix A: Mechanical dimensions............................................................................... 31
Appendix B: Detector geometries..................................................................................... 32
Appendix C: Mapping between APD pixels and ADC channels ..................................... 34
Appendix D: Connector pin-outs...................................................................................... 41
Appendix E: ADC register map........................................................................................ 43
Appendix F: Control unit register map............................................................................. 45
Appendix G: 10Gbit communication and timing card Instructions.................................. 47
Appendix H: 10G communication and timing unit registers............................................ 52
Appendix I: Using the APDTest program ........................................................................ 56

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1. Using this document
This manual is intended for users of the APDCAM-10G avalanche photodiode cam-
era. As a start users should read sections 2-4 as it gives a brief introduction to system
capabilities and operation.
Section 5 contains a reference manual which is intended for advanced users and pro-
grammers. The Application Programming Interface is described in a separate document.
Section 6 (troubleshooting) gives some hints what to do if the camera does not behave
as it is expected.
Section 7 contains a table of possible versions of the camera and the Appendix A-I
detail mechanical, software and other interfaces.

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2. Overview
2.1. The APDCAM family
The APDCAM family of products are ultrafast avalanche photodiode (APD) matrix
detector devices containing all detector infrastructure and data acquisition in one compact
package, connecting to a computer via 1 or 10 Gbit Ethernet interface. This type of detec-
tor is designed for special applications where low light level has to be measured with
extreme high speed (up to several MHz). The APDCAM family uses the Hamamatsu
S8550 4x8 detector array having large area pixels (1.6x1.6 mm) compared to CCD sen-
sors therefore they are easier to match to low f-number optics used in low light applica-
tions. All pixels of the detector are read out simultaneously; therefore the throughput is
not limited by readout time. The intrinsic gain of the detector allows measurement under
conditions where photodiodes would not be applicable and stable gain is provided by the
temperature stabilised detector.
APDCAM uses one 4x8 pixel detector and connects to the computer via 1 Gbit Ether-
net, while APDCAM-10G can use up to 4 detector matrices, that is 32 to 128 pixels. Dif-
ferent arrangements are possible: 8x8, 4x16, 4x32, 8x16 all using the same 10 Gbit
Ethernet interface.
2.2. Overview of APDCAM-10G
APDCAM-10G has a modular layout with detector amplifiers and digitizers available
in 32 channel blocks. The detector arrangement, the amplifier analog parameters and
many other options can be specified at order time, see in the Order options section. Each
APD pixel has its individual analog amplifier and 14 bit digitizer which runs all the time.
The resulting data stream can be digitally filtered and down-sampled before sending to
the computer in UDP packets. At present only Linux operating system is supported as
ordinary Windows systems cannot handle the maximum throughput rate. (The 32 channel
APDCAM system is supported under Windows as well.) Data is transferred to the com-
puter in real time, thus the amount of data is limited only by computer memory. The max-
imum data rate depends on the number of active channels, for the maximum configura-
tion of 128 channels 3 MHz is available.
Although the S8550 detector matrix has a fill factor of 50% only, an optional micro-
lens array can be mounted on it to increase detection efficiency close to 100%, depending
on the optical input imaging.
Various triggering and sampling schemes are available for the data acquisition, includ-
ing external, internal, post-trigger, external sample control. Optional fibre-to-electrical
interfaces can be installed in the camera to be able to use triggering/sampling signals di-
rectly in digital optical format.
To help alignment and testing APDCAM-10G has an array of LEDs and optional opti-
cal fibres around its detectors. LEDs can be used for both alignment by back illuminating
to the object space or for testing as calibration light source. Optical fibres lead light to the
back of the camera where e.g. it can be connected to spectrometers.
Technical specifications of the system are shown in Table 1. and Table 2. Figure 1.
shows photos of the APDCAM10G system.

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Detector
Detector type
Avalanche Photodiode array
Hamamatsu S8550, 2 or 4 arrays/camera
(micro-lens array optional)
Pixel arrangement
8 x 8, 4x16, 4x32, 8x16 (order option)
Pixel size
1.6 x 1.6mm
Pixel pitch
2.3 mm
(2.6 mm between 2x8 sub-arrays inside de-
tector, 4.3 mm between detectors)
Fill factor
50%
Spectral response range
300 to 1000 nm
Peak quantum efficiency
85% typical at 650 nm
Detector Gain
Typical 50, max 100
Temperature control range1
Typical 10...30 ºC
Temperature control type
Peltier, cooling/heating
Micro-lens array (Optional)
Material
Zeonex
Arrangement
2x8 aspherical lens matrix
Mounting
Non-detachable with UV hardening optical
glue. Each 2x8 array is adjusted to 2x8 de-
tector sub-array
Lens height above detector surface
2.3 mm
Optical fibres in detector head (Optional)
Diameter
1 mm, bunch of 10 micron optical fibres
Numarical Aperture (NA)
0.55
Typical detector sensitivity and noise
Sensitivity @ Gain=100, 14 bit mode2
2.4 106 photon/s/digit
Noise equivalent photon flux @ no light2
Typical 5 107 photon/s
Analog bandwidth2
1 MHz
Digitizer
Internal sampling rate / bits
10-25 MHz / 14 bits
Digital filter
5-point FIR + 1stage recursive
Output bits
14/12/8 (MSB from internal 14 bits)
Ring buffer
0...1024 samples/channel
Trigger
Internal/External TTL/software
Trigger delay
1µs....1000s
Resampling control
Internal fixed divider or external TTL input
Clock base
Internal 20 MHz or external
Table 1. Technical specifications of APDCAM-10G, part 1.
1
Temperature range depends on ambient temperature.
2
Standard setting. Sensitivity and bandwidth can be specified at order time. Selection affects noise level.

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Table 2. Technical specifications of APDCAM-10G, part 2.
3
Weight depends on order options
Data transmission
Data and control interface
10 Gigabit Ethernet
Optical module form factor
XFP (camera provides 5V power but no
clock for the transceiver)
Communication format
UDP, both directions
Max. data rate @ 128 channels
4 MHz/14bit
Max. data rate @ 64 channels
6 MHz/14bit
Power supply unit
Power input
19-24 V DC, max. 180 W
Size (W,H,D)
32x22x27 cm
Camera mechanical dimensions
Size (L,W,H)
497*160*185 mm
Weight without power supply3
8 kg

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3. System components
The APDCAM-10G system consists of the camera, the power supply unit and a mains
adaptor as shown in Fig. 1. The mains adaptor is a high-power laptop power supply or it
can be substituted by any suitable 19-24 V DC power supply.
The APDCAM-10G power supply unit converts the single 19-24V input voltage from
the mains adaptor to several voltages required by the camera. These voltages are connect-
ed to the camera through the power cable. The cable length can be between 1-10 m, spec-
ified at order. The power supply unit is set for the given camera configuration and cable
length. Using a shorter cable is possible at the expense of increased camera temperature.
Using longer cable might require adjustments in the power supply unit.
Connectors and indicators are located on the back of the camera, as shown in Fig.2.
Table 3. contains brief information on these elements, more details are found in the fol-
lowing chapters.
Mains
adaptor
Backplate with
connectors and indicators
APDCAM-10G
Front face
Power
cable
Power supply
unit
Figure 1. View of the APDCAM-10G system components.
Detectors
Calibration
LEDs
Optics
mounting
holes
Power
connector
Extension
panel
Connectors
and
indicators
10Gbit
Ethernet
Service
connector

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Figure 2. Connectors and indicators on the backside of the camera.
Reset but-
ton
External
clock in
External
clock out
Trigger
in
External
sample
in
Trigger
out
Optional IO
signals

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Controls
Reset button
This depressed button can be operated with a pen or other pointed
device. Pressing it causes the camera to return to factory default
settings.
Connectors
Power connector
Receives input power from the power module.
Clock in
Reference TTL clock input. Synchronises clock base of APDCAM
to external source. (Signal standard 3.3 V CMOS)
Clock out
Reference clock output. Can be used to synchronize clock base of
external device. (Signal standard 3.3 V CMOS)
Trigger in
Data acquisition start trigger signal input.
(Signal standard 3.3 V CMOS)
Trigger out
Outputs High level while data transmission is active.
(Signal standard 3.3 V CMOS)
Sample in
Input resample clock. (Signal standard 3.3 V CMOS)
Opt
Optional input-output. Can be selected among various internal sig-
nals in the factory.
Optical interface
An XFP form factor transceiver is installed in this place which pro-
vides 10Gbit optical Ethernet interface to the PC.
Ethernet UTP
UTP cable connection only for factory testing.
LEDs
Temp.
Red light means temperature alarm. Some element of the camera is
overheated.
Overload
Red light means overload condition occurred, detector bias voltage
is switched off. (Optional)
Comm.
Green light flashes when control communication occurs between
PC and camera
DAQ
Data acquisition module state: Green: normal state, red: error
Control
Control module state: Green indicates normal state, red means error
condition.
Calib.
Yellow light means calibration light is on.
Shutter
Yellow light means shutter is open. (Shutter is optional.)
HV
Blue light means detector bias voltage is on.
Ext. Clock
Green light means external reference clock signal is accepted.
Data out
Green light indicates data output to PC.
Link Up
10Gbit communication established
Comm.
Communication to PC.
Extension card
The extension card can hold SMA fibre connectors, optical-to-TTL repeaters and combi-
nations of them.
Optical fibre con-
nectors
These are the (optional) SMA connections to the optical fibres in-
stalled in the detector head.
Optical receiver
These modules can be used for fibre connections to/from trigger
and clock signals.
Table 3. List of controls, connectors and LED indicators of APDCAM-10G.

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4. Using APDCAM
4.1. Operating environment
APDCAM-10G is a highly sensitive instrument, therefore some effort might be need-
ed in the setup to minimise noise pick up by the camera. Although APDCAM-10G is
housed in a grounded Aluminium enclosure and the detector and analog amplifiers are
housed in an additional Faraday shield strong environmental electrical noise sources
might cause disturbances in the signals. To avoid such conditions separate the camera
ground from noisy electronic equipment.
The camera housing and electronics is connected to electrical ground on the power
supply mains connector. However, the electronics is grounded only at the camera head. It
is advisable to avoid ground connection between the electronics (e.g. the transceiver
module or Lemo connectors) and the camera backplate as is increases the noise sensitivi-
ty.
4.2. Power connection
APDCAM-10G is delivered with a mains adaptor which can be operated from 100 to
240 V mains voltage. This unit has a replaceable power chord, please use one which
matches your local mains outlet. The mains adaptor has a 7-pin Hirose plug, this needs to
be connected to the APDCAM-10G power supply unit.
The camera is connected to the power supply unit via the shielded power cable. The
cable has two identical 16 pin Hirose plugs on both ends. The shielding is connected to
the signal ground at one end only, which is marked on the plug. From noise suppression
point of view it is advisable to connect the end with the shield connection to the power
supply unit.
The camera can be powered up with the mains switch on the front of the power supply
unit, no power switch is located on the camera itself. After switching on the power the
“Power OK” LED on the power supply unit should be lit, indicating that all the voltage
necessary for the camera are available. On the camera all LEDs should blink in the pow-
er-up procedure and finally the “DAQ” and “Control” green LEDs should light up indi-
cating that both the data acquisition system and the control system are ready for opera-
tion.
4.3. Camera cooling
APDCAM-10G has three independent fans on the top of the device which circulate air
from the openings on the lower part of the camera out through the fans. The openings
should be free to provide the necessary air flow. The camera might be delivered either
with fixed fan speed or software adjustable fan speeds. In both cases the fan speeds are
set to maximum during manufacturing. If the camera is configured for adjustable fan
speed lower speed can be set through the software interface. In this case the user is re-
sponsible for setting a minimum fan speed for sufficient cooling.