SPMMicro High Gain APD Version 2.03

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1 Overview SensL s SPMMicro is an entry level and encapsulates SensL s world-leading APD technology in a miniature, easy to use, low cost platform. The device is available with a range of preamplifier boards and with the sensor packaged in a T8 can. The SPMMicro is available with active areas of 1mm x 1mm or 3mm x 3mm. The responsivity of 6, A/W is many orders of magnitude higher than can be achieved from other silicon detectors. Even at the extreme end of silicon capability in the classic eye safe and LIDAR wavelength of 164nm the responsivity is still 1A/W which is substantially higher than existing detectors. The SPMMicro has the well appreciated benefits of silicon detectors, including size, low operating voltage, robustness, reliability, magnetic insensitivity and suitability for miniaturisation. In addition, the novel design is tolerant to excess/ambient light, has a very fast pulse response, has low excess noise and high S/N ratio. The benefits of the SPMMicro vs. industry standard Silicon APDs are shown in the table below. These significant performance enhancements combined with the ease of integration, compact and miniature form factor and low cost makes the SPMMicro the ideal low light analogue detection platform for OEMs. Furthermore, planned enhancements to the SPMMicro provide a roadmap to even greater benefits in future product generations. The technology, known as a Silicon Photomultiplier (SPM), is based on arrays of SensL s high gain photodiodes. The pulses of current from each high gain photodiode (each with an intrinsic gain of 1 6 ) are summed together at the output giving an analogue output signal which is proportional to the number of photodiodes responding to input photons. The output is proportional to the incident light flux on the sensor. The very high gain combined with a high photon detection probability results in the world leading responsivity. The SPMMicro is available with a variety of amplifier circuits, including a transimpedance option for CW applications, and a preamplifier for pulsed applications. The signal to noise of the SPMMicro is better than an APD for many typical applications. This is possible due to the superior excess noise of the Silicon Photomultiplier technology. A direct comparison of the S/N between a PMT and SPMMicro is shown in Page 8 Features High gain Silicon APD (1 6 ) Very high responsivity (6,A/W) Low bias voltages (3V) Fast rise time (<5s) Fast recovery time (<2ns) Superior S/N to normal APDs Not damaged by excess/ambient light Large area 1mm 2 and 9mm 2 options Minimal electronics requirement Compact, rugged and stable Insensitive to magnetic fields Applications Biological sensors Scanning microarrays DNA biochips/sequencing Proteomics/Protein Biochips Point-of-use biological agent detection Environmental monitoring Nuclear radiation detection Homeland security Flow cytometry Range finding Targeting LIDAR Food Inspection Technology Comparison SPM Normal Silicon APD High gain (1 6 ) Low gain (1 2 ) Low bias voltage (3V) Peak Responsivity 164nm (1,A/W) Tolerant of excess ambient light Higher bias voltage (8V) Peak Responsivity 164nm (3A/W) Damaged by excess ambient light Page 1

2 Mechanical Information: Location of Detector Surface 4.14 All dimensions in mm Ordering Information SPMMicro1X1A1 Module Base: Transimpedance Amplifier & 1mm x 1mm sensor in T8 Can SPMMicro1X1A3 SPMMicro3X1A1 SPMMicro3X1A3 Module Base: Pulse Amplifier & 1mm x 1mm sensor in T8 Can Module Base: Transimpedance Amplifier & 3mm x 3mm sensor in T8 Can Module Base: Pulse Amplifier & 3mm x 3mm sensor in T8 Can Page 2

3 Technical Information - Silicon Photomultiplier Concept Overview The core of SensL's SPM product line is a high gain photodiode array. SensL's photodiodes are specially designed to allow for operation above the breakdown voltage. Operation above breakdown is known to produce incredibly large gains (up to 1 6 ), which allow SensL's photodiodes to be sensitive to single photons of light. Internally, what allows a SensL photodiode to detect single photons is an ultra-high quality silicon diode coupled with a quenching resistor. The simplest way to view this concept is through the figure below. In this figure, a single diode is connected in series with a passive quenching resistor. When photons enter into the diode, they cause a very uniform avalanche breakdown to occur. This breakdown is then quenched by the series resistor. By carefully controlling the diode formation and resistor uniformity, a uniform pulse of current flows through the diode during each photon event. This process is the result of years of work into single photon counting diodes and allows high performance highly sensitive detectors in silicon to be realised. In the Silicon Photomultiplier a large number of these high gain photodiodes are connected in parallel summing the output current from all the active pixels. Each photodiode operates on its own in response to photons entering into the detector. This is shown below as a schematic and also as an image from a manufactured SPM. The end result when illuminated is an analogue signal representing the current pulses from all the photodiodes within the array. This analogue output signal is therefore proportional to the light incident on to the active area of the sensor at any instant in time. Time Technical Information - Pre-Amplifier Options To benefit from the high gain responsivity it is required to use circuitry which can convert the current flowing through the array into a voltage which can be readily processed with standard electronics. Given the high gain inherent in the SPM, it is possible to use pre-amplifier boards of either current or voltage amplification. This has resulted in two different pre-amplifier configurations available from SensL. Transimpedance Amplifier The first of these is a transimpedance type pre-amplifier which can convert the raw current from the SPM into a voltage. The typical gain for a SensL transimpedance amplifier is 47V/A. The transimpedance pre-amplifier board is shown schematically in the Figure below. This board is ideal for applications that require detection of continuous signals where integration of the signal is done over time. One application is cell imaging or DNA microarrays where it is desired to integrate the optical signal from a sample for periods from 1us to 1ms in time. This can be accomplished easily with the SensL Transimpedance pre-amplifier. Page 3

4 The typical response of the detector to a light signal with the transimpedance amplifier is shown in the images below. The image on the left shows the response of a 1mm SPMMini device with a transimpedance amplifier to a low photon level, i.e. small optical signal. The image on the right shows the response of the same device to a large signal (close to sensor saturation). Response of 1mm Device with Transimpedance Amplifier to Small Optical Signal.5 Response of 1mm Device with Transimpedance Amplifier to Large Optical Signal 5.E-2.E+ -5.E-2 Amplitude (V) Amplitude (V) -1.E-1-1.5E-1-2.E-1-2.5E-1-3.E E-1-4.E E-5 2.7E-5 2.9E-5 3.1E-5 3.3E-5 3.5E-5 3.7E-5 3.9E-5 Time (secs) -4.5E-1-5.E-7.E+ 5.E-7 1.E-6 1.5E-6 2.E-6 2.5E-6 Time (s) Pulse Amplifier In situations where the signal is a pulse input, such a ranging applications, a scintillation experiment or in high energy physics, SensL have developed the pulse amplification pre-amplifier. This board is shown in the figure below. This allows the fast rise time of the detector to be exploited and provides for the simplest way to accurately bring pulse information to the user. The SensL SPM is coupled to a high speed pulse pre-amplifier which uses an internal gain of 2. This signal is then output to the user via a DC blocking capacitor to properly convey pulse information originating in the SPM. The typical response of the detector to a pulse light signal with the pulse amplifier is shown in the images below. The image on the left shows the response of a 1mm SPMMicro device with a pulse amplifier to a very low level photon pulse. The leading edge is ~5ns and trailing edge is ~2ns. The image on the right show the response of the same device to a large optical signal (close to sensor saturation). Amplitude (V) Response of 1mm Device with Pulse Amplifier to Small Optical Signal E+ 2.E-8 4.E-8 6.E-8 8.E-8 1.E-7 1.2E-7 1.4E-7 1.6E-7 1.8E-7 Time (s) Amplitude (V) Response of 1mm Device with Pulse Amplifier to Large Optical Signal E-7-1.5E-7-1.E-7-5.E-8.E+ 5.E-8 1.E-7 1.5E-7 2.E-7 2.5E-7 3.E-7 Time (s) Page 4

5 General Specifications Parameter Min Typical Max Unit s Test conditions INPUTS Input Voltage 1 (+5V) V Typical Current 5mA Input Voltage 2 (-5V) V Typical Current 5mA Input Voltage 3 - Detector Bias Voltage V Typical Current 1mA Breakdown Voltage (V br ) V At Room temperature OTHER Spectral range 4 11 nm Peak λ = 52nm Max Operating Temperature -2-4 C Max Storage Temperature C Specific Specifications Typical Values SPMMicro1X1A1 SPMMicro1X2A1 Part Number SPMMicro1X1A3 SPMMicro1X2A3 SPMMicro3X1A1 SPMMicro3X2A1 SPMMicro3X1A3 SPMMicro3X2A3 Units Test conditions Chip Area 1.14x x1.14 mm 2 - Active Area 1x1 1x1 mm 2 - Responsivity 6, 6, A/W +4V above breakdown, λ = 52nm Pixel Gain 1.1x x1 6 - Bias = 32V Pre-amp Board Gain 47V/A 2-5Ω load Max Output Voltage V 5Ω load NEP 9.7x x1-15 WHz -1/2 +4V above breakdown, λ = 52nm Dynamic Range Bias = 32V, λ = 65nm Linear Range nw/mm 2 Bias = 32V, λ = 65nm Cut-off Freq 1 11 MHz 3dB point Number of Pixels Pixel Efficiency (QE) 5 5 % λ = 52nm, V = 32 Geometrical Efficiency (F) % - Photon Detection Efficiency (QExF) % λ = 52nm, V = 32 Temp. dependence of Voltage Breakdown mv/ o C - Single Photon Pulse - Leading Edge 2 5 ns Small optical pulse Single Photon Pulse - Falling Edge 23 2 ns Small optical pulse Pending Pending Notes: SensL reserves the right to change all product specification and functionality without notification. Information on this datasheet is believed to be accurate. However, no responsibility is assumed for any inaccuracies or omissions. The printed version of this datasheet is restricted to two pages. The full version is available on our website at Page 5

6 Technical Information - Responsivity The Responsivity of the SPMMicro, measured as A/W, is shown below for each of the SPMMicro product sizes. This shows that the results are many orders of magnitude higher than other solid state devices, and comparable to the performance of a PMT but with all the benefits of a silicon platform (size, portability, robustness, reliability, low voltage). Responsivity vs. Wavelength (for each product size) All 1mm Devices Responsivity (A/W) At λ = 164nm = 12A/W Wavelength (nm) Responsivity Comparisons The responsivity of the SPMMicro is compared to that of existing detector technologies in the table below. All measurements are made using a continuous light source, a monocromator and an integrating sphere. Calibration is via a calibrated PIN diode. Parameter Peak Responsivity Form Factor/ Portability Reliability/ Robustness Operating Voltage APD (Blue Optimised) N/A Miniature Small & Portable 1-2V APD (Red Optimised) 3A/W Miniature Small & Portable 5-8V Photomultiplier (PMT) N/A Large, Glass Tube Fragile/Calib Required 1-2kV SPMMicro (Transimpedance) 164nm Responsivity 1,2 A/W Miniature Small & Portable 3V Impact of Overexposure None Damaged Damaged None Technical Information - Bandwidth SPMMicro The image below shows the bandwidth of the 5 Bandwidth (λ = 52nm, Over-bias = 4V) Amplitude (mv) SPMMicro1X1A1/SPMMicro1X2A (All 1mm with Transimpedance Option) SPMMicro1X1A3/SPMMicro1X2A3 (All 1mm with Pulse Option) E+3 1.E+4 1.E+5 1.E+6 1.E+7 1.E+8 Frequency (Hz) Page 6

7 Technical Information - Gain Control The gain can be varied by adjusting the over bias voltage (i.e. the Over Voltage or the voltage above the breakdown voltage). 2.5 Gain Control - Gain vs. Bias Voltage (λ = 55nm, all 1mm devices) 2 Gain (x 1 6 ) All 1mm Devices Bias (V) Technical Information - Dynamic Range The SPM response as a function of input optical power is shown for all the SPMMini product variations. The Dynamic Range is the range of optical input power signals which the detector can measure. This is measured by measuring the detector output response to varying optical input signal power. The upper limit of the Dynamic Range is the power level at which the detector is saturated, i.e. all the photodiodes are continuously firing. Output Voltage (mv) Dynamic Range (λ = 55nm, Over - bias = 4V) 2 SPMMicro1X1A1 (Transimpedance Option) 1 SPMMicro1X1A3 (Pulse Option) Optical Power (nw/mm 2 ) From the data on the left side it can be seen that the Measurement Range of the SPMMini is four orders of magnitude. 1 Measurement Range (λ = 55nm, Over - bias = 4V) Output Voltage (mv) 1 1 SPMMicro1X1A1/SPMMicro1X2A1 (All 1mm Devices with Transimpedance Option) SPMMicro1X1A3/SPMMicro1X2A3 (All 1mm Devices with Pulse Option) Optical Power (nw/mm 2 ) Page 7

8 Technical Information - Noise Noise Equivalent Power (NEP) is derived from dark rate data. This is when the signal rate is equal to the dark rate, i.e. the signal to noise is E-14 NEP vs. Bias Voltage (λ = 55nm) Noise Equivalent Power (WHz -1/2 ) 1.2E E-14 1.E-14 9.E-15 8.E-15 7.E-15 6.E-15 5.E-15 All 1mm Devices 4.E Bias (V) Technical Information - Signal to Noise The following chart compares the S/N for a PMT, a photodiode and the SPMMicro at various light levels. Signal to Noise Ratio Page 8

9 About SensL SensL's vision is to become the brand and partner of choice for users (particularly OEMs) of low light detectors and imaging systems. Our disruptive products facilitate the improvement in the performance of our customers systems and enable new applications by overcoming the limitations of existing low light detector technologies. This is particularly relevant when compared to the vacuum based Photomultiplier Tube (PMT). This breakthrough in low light detection solutions has been achieved by leveraging our core Geiger Mode Photodiode technology to create three distinct low light detector platforms. Our Photon Counting, Silicon Photomultiplier and Low Light Imager products enable the development of new systems for applications such as Bio-diagnostics, Medical Imaging, LIDAR, Environmental Monitoring and High Energy Physics. Sales Channels and Partners Europe, Middle East, Africa Belgium Laser 2 BeNeLux S.A. Rue du Moulin Fraire tel. +32 / sales@laser2.be web: Israel Lahat Technologies Ltd. Teradion Industrial Zone Misgav 2179 tel: sales@lahat.co.il web: Spain LASERTechnology, S.L. Poligono Industrial LaBaileta, CalleB Nave Cabrils, Barcelona tel: info@laser-technology.com web: France Laser 2 S.A.S. Parc d'affaires,3 rue de la Plaine 7886 Saint-Nom la Bretèche tel: +33 / 1 / info@laser2.fr web: Italy UNIFIBRE s.r.l. Via Salvemini Settimo Milanese (MI) tel: uniteam@unifibre.it web: Sweden Laser 2 AB Box Norrköping tel info@laser2.se web: Germany Laser 2 GmbH Argelsrieder Feld 14 D Wessling, München tel: contact@laser2.de web: Netherlands Laser 2 BeNeLux C.V. Voorbancken 13a, PO Box ZJ Vinkeveen tel: +31 / 297 / info@laser2.nl web: Switzerland GMP SA Av. Des Baumettes 17 CH-12 Renens tel: info@gmp.ch web: United Kingdom Laser 2 (UK) LTD Britannia House, Denford Road Ringstead, Kettering, NN14 4DF tel: +44 () sales@laser2.co.uk web: USA, Canada USA (West Coast) Market Tech, Inc. P.O. Box 6737, Scotts Valley, CA tel: info@markettechinc.net web: USA (East Coast) Blue Hill Optical Technologies 48 Washington Street #7, Norwood, MA 262 tel: sales@bluehilloptical.com web: Canada Gamble Technologies Ltd Millcreek Drive, Unit #71 Mississauga, ON L5N 2M2 tel: info@gtl.ca web: Asia-Pacific Korea SeongKyeong Photonics. Ma-22, 399-8, Daeduk Hi-tech B/D, Doryong-dong, Yuseong-gu, Daejeon, tel: yoon@skphotonics.com web: China Shanghai Weining Technology Development Co., Ltd Changan Road, Suite 24D, Chongfang East China Tower, Shanghai, 27 tel: jamesxu25@126.com web: Japan Tokyo Instruments, Inc Nishi-Kasai, Edogawa-Ku Tokyo tel: sales@tokyoinst.co.jp web: Page 9