EMCCD Publications And Scientific Papers
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EMCCD Cameras Take Imaging To A New Level
High-end cooled digital cameras featuring electron multiplying CCD technology are
revolutionizing our ability to image very weak photon fluxes successfully, says
Colin Coates.
Continual advancements in imaging and spectroscopy are placing unprecedented demands
on camera technology to perform at significantly higher levels. Techniques such
as intracellular ion signalling microscopy (e.g. Ca2+ flux microscopy) and multidimensional
(4–5D) microscopy on live cells impose considerable demands on detection technology,
in terms of higher sensitivity at faster frame speeds.
Electron multiplying charge-coupled device (EMCCD) camera technology has been designed
to respond to this growing need. Download Article
Seeing From One To One Million Atoms
By Dr. Paul Griffin and Prof. Michael Chapman, School of Physics, Georgia Institute
of Technology, and Dr. Colin Coates, Andor Technology Plc
Electron multiplying CCD (EMCCD) scientific digital camera technology is used to
image an extremely cold nano-climate, found in the laboratories of Professor Mike
Chapman at the School of Physics, Georgia Institute of Technology. Chapman and his
group focus on investigating the quantum behavior of atoms and photons, often at
the single particle level. Cooling bosonic atoms to a very low temperature, beyond
a critical temperature for the atom, causes them to condense into the lowest available
quantum state, resulting in a new wavelike form. In this state, a cloud of atoms
will form a macroscopic quantum state in which all the atoms share the same space
and have phase coherence in their wavefunctions. Lasers are employed to confine
and cool such atoms to nano-Kelvin temperatures (colder than the most remote regions
of deep space, which are pervaded by cold microwave radiation — the afterglow of
the Big Bang). The cooled atoms are used for studies including fundamental atom-photon
interactions, atom optics and interferometry, and quantum computing (towards a future
generation of supercomputers) and communication. Recent achievements of the Chapman
Research Lab include the first all-optical Bose-Einstein Condensation (BEC), the
first storage ring for neutral atoms, and cavity QED with optically transported
ultracold atoms. Read more
Making Sense of Ultra-Sensitivity - Converstory
The Back-Illuminated Electron Multiplying CCD
The trend in instrument performance across a wide range of scientific CCD-based
imaging applications is moving very much towards higher sensitivity at faster speed,
enabling lower concentrations of emitting molecules to be detected with shorter
exposure times and lower excitation powers. The true nature of sensitivity and its
relationship to Signal to Noise (S/N) is often misunderstood or misrepresented.
Dr. Colin Coates, Andor Technology's Application Specialist for Low Light Imaging
breaks down the concept of sensitivity to it's fundamental parameters and describes
how recent revolutionary developments in CCD technology are influencing these parameters,
culminating with the latest prolific advancement, the Back-Illuminated Electron
Multiplying CCD. The combination of technologies incorporated into this camera range
enable, literally, the world's most sensitive detectors Download Publications
Ultra-sensitivity, speed and resolution: Optimizing low-light microscopy with the
back-illuminated electron multiplying CCD
Colin G. Coates, Donal J. Denvira, Noel G. McHaleb, Keith D. Thornbury and Mark
A. Hollywood.
Andor Technology Ltd. Belfast, Smooth Muscle Group, Medical Biology Centre, Queen’s
University of Belfast.
The back-illuminated Electron Multiplying Charge Coupled Device (EMCCD) camera is
having a profound influence on the field of low-light dynamic cellular microscopy,
combining highest possible photon collection efficiency with the ability to virtually
eliminate the readout noise detection limit. We report here the use of this camera,
in 512 x 512 frametransfer chip format at 10 MHz pixel readout speed, in optimising
a demanding ultra low-light intracellular calcium flux microscopy set-up. The arrangement
employed includes a spinning confocal Nipkow disk, which whilst facilitating the
need to both generate images at very rapid frame rates and minimize background photons,
yields very weak signals. The challenge for the camera lies not just in detecting
as many of these scarce photons as possible, but also in operating at a frame rate
that meets the temporal resolution requirements of many low-light microscopy approaches,
a particular demand of smooth muscle calcium flux microscopy. Results presented
illustrate both the significant sensitivity improvement offered by this revolutionary
technology over the previous standard in ultra low light CCD detection, the GenIII+
ICCD, and also portray the advanced temporal and spatial resolution capabilities
of the EMCCD. Download paper
Back-illuminated electron multiplying technology: The world’s most sensitive CCD
for ultra low-light microscopy
Colin G. Coates, Donal J. Denvir, Emer Conroy, Noel McHale, Keith Thornbury and
Mark Hollywood.
Andor Technology Ltd. Belfast, Smooth Muscle Group, Medical Biology Centre, Queen’s
University of Belfast,
The back-illuminated Electron Multiplying Charge Coupled Device (EMCCD) camera stands
to be one the most revolutionary contributions ever to the burgeoning fields of
low-light dynamic cellular microscopy and single molecule detection, combining extremely
high photon conversion efficiency with the ability to eliminate the readout noise
detection limit. Here, we present some preliminary measurements recorded by a very
rapid frame rate version of this camera technology, incorporated into a spinning
disk confocal microscopy set-up that is used for fast intracellular calcium flux
measurements.
The results presented demonstrate the united effects of: (a) EMCCD technology in
amplifying the very weak signal from these fluorescently labelled cells above the
readout noise detection limit, that they would otherwise be completely lost in;
(b) back-thinned CCD technology in maximizing the signal/shot noise ratio from such
weak photon fluxes. It has also been shown how this innovative development can offer
significant signal improvements over that afforded by ICCD technology. Practically,
this marked advancement in detector sensitivity affords benefits such as shorter
exposure times (therefore faster frame rates), lower dye concentrations and reduced
excitation powers and will remove some of the barriers that have been restricting
the development of new innovative low-light microscopy techniques. Download paper
Electron Multiplying CCD Technology: The new ICCD
Donal J. Denvir, Emer Conroy Andor Technology Ltd. UK
A novel CCD has been commercially produced by Marconi Applied Technology, UK under
the trade name of L3Vision, and by Texas Instruments, USA under the trade name Impactron,
both of which incorporate an all solid-state electron multiplying structure based
on the Impact Ionisation phenomenon in silicon. This technology combines the single
photon detection sensitivity of ICCDs with the inherent advantages of CCDs.
Here we compare the electron multiplying CCD (EMCCD) with scientific ICCDs. In particular
we look at the effect of the Excess Noise Factors on the respective S/N performances.
We compare QEs, spatial resolution, darksignal, EBI and Clock Induced Charge (CIC),
with the latter two as the ultimate limitations on sensitivity. We conclude that
the electron multiplying CCD is a credible alternative to ICCDs in all non-gated
applications. Download
Paper
Low light level CCDs and visibility parameter estimation
A. G. Basden and C. A. Haniff Astrophysics Group, Cavendish Laboratory, Madingley
Road, Cambridge
Recently, low light level charge-coupled devices (L3CCDs) capable of on-chip gain
have been developed, leading to subelectron effective readout noise, allowing for
the detection of single photon events. Optical interferometry usually requires the
detection of faint signals at high speed and so L3CCDs are an obvious choice for
these applications. Here we analyse the effect that using an L3CCD has on visibility
parameter estimation (amplitude and triple product phase), including situations
where the L3CCD raw output is processed in an attempt to reduce the effect of stochastic
multiplication noise introduced by the on-chip gain process.We establish that under
most conditions, fringe parameters are estimated accurately, whilst at low light
levels, a bias correction which we determine here may need to be applied to the
estimate of fringe visibility amplitude. These results show that L3CCDs are potentially
excellent detectors for astronomical interferometry at optical wavelengths. Download Paper
Optimization of Spinning Disk Confocal Microscopy: Synchronization with the Ultra-Sensitive
EMCCD
F. K. Chonga, Colin G. Coates, Donal J. Denvir, Noel McHale, Keith Thornbury and
Mark Hollywood. Andor Technology Ltd., Smooth Muscle Group, Medical Biology Centre,
Queen’s University of Belfast
The advent of Electron Multiplying Charge Coupled Device (EMCCD) technology and
it’s ability to overcome previous hurdles in low-light fluorescence microscopy,
such as phototoxicity to live cells, photobleaching of fluorophores and exposure
time restrictions, has resulted in a significant resurgence of interest in use of
confocal spinning disk techniques for live cell microscopy. Here provide an understanding
of, and technical solutions to, the issues of synchronization that have previously
marred the coupling of fast CCD camera technology to confocal spinning disk arrangements.
We examine the challenges arising from both old and new models of the Nipkow spinning
disk confocal unit and suggest solutions throughout based on a sound comprehension
of both (a) relative scan/exposure times; (b) relative orientation of the coupled
devices; (c) optimisation of EMCCD clocking parameters. Download Paper