02 Jul 2009
A new CMOS image sensor for the first time challenges the highest-performing imaging devices for scientific applications.
In a rare example of effective collaboration between competing companies, three imaging specialists have joined forces to set a new performance benchmark for CMOS image sensors. The new technology, dubbed scientific CMOS (sCMOS), for the first time combines high speed and high resolution with a wide dynamic range, large field of view, and the ability to operate effectively in low-light levels.
The new sCMOS technology is the brainchild of three recognized imaging specialists: Andor Technology of Belfast, Northern Ireland; Fairchild Imaging of Milpitas, California; and PCO Imaging of Kelheim, Germany. "This is a great moment for all three companies, who have come together in a true spirit of commitment to reach a shared goal," said Colin Earle, Fairchild Imaging’s vice-president for sales and marketing.
At a news conference to launch the technology, Andor’s Colin Coates explained that existing image sensors are unable to meet all the requirements of many scientific applications. "Trade-offs must always be made," he said. "For example, low noise levels and high resolution can only be achieved at the expense of low frame rates."
Coates compared the capabilities of sCMOS image sensors to two leading commercial rivals: an interline charge-coupled device (CCD), which is a popular choice for cell imaging applications, and a high-end electron-multiplying CCD (EMCCD) camera. "sCMOS challenges both EMCCD and interline as a value proposition for OEM and research applications," he claimed.
According to Coates, sCMOS is unique in delivering all the key imaging parameters at the same time:
High speed: 100 frames/s, compared with around 30 frames/s for EMCCD devices and 12 frames/s (at 20 MHz) for interline CCDs.
Low noise: less than 2 e– at 30 frames/s and less than 3 e– at 100 frames/s. For comparison, an interline CCD has higher noise levels of 4–8 e–, while an EMCCD achieves negligible noise levels and remains the best choice for high sensitivity in extremely low light levels.
Wide dynamic range: 16,000:1 at 30 frames/s. An EMCCD achieves 8500:1 at the same frame rate, while an interline CCD is limited to 3000:1 at 11 frames/s.
High resolution: pixel size of 6.5 µm, which is comparable to both interline and EMCCD devices.
High quantum efficiency: at 60%, the quantum efficiency of sCMOS is comparable to that offered by interline CCDs and EMCCDs.
Coates acknowledged that sCMOS cannot achieve the extreme high sensitivity offered by EMCCD cameras, but believes that its low-light performance is good enough for many applications. The pricing of sCMOS will therefore be positioned to be less expensive than EMCCD, but more expensive than interline imaging devices.
Although the companies have worked together to create the enabling technology, they will go their separate ways when it comes to commercialization. Fairchild plans to release the first iteration of its sCMOS imaging device later this year, while Andor and PCO will launch products early in 2010.