Photon counting head

Hamamatsu Photonics has developed a new photon-counting head with lens by applying its capabilities in photomultiplier tubes (PMT) and optical design technology. The photon counting head, ‘H10682-110W’, is integrated with a newly designed condenser lens offering high light-collecting efficiency while using a thin profile. Its sensitivity is 5 times superior to its currently available products, though still maintaining the same small size.

The H10682-110W can be installed into compact in-vitro diagnostic instruments to increase their sensitivity. This reduces the amount of blood and other specimens that need to be collected from patients while still providing the same accuracy, making testing more comfortable. Another benefit is the shorter measurement time which will lower the workload of medical staff.

Hamamatsu Photonics has been manufacturing and selling small-sized photon counting heads with a photosensitive area of 8mm in diameter. However, the amount of light entering this small photosensitive area is low and insufficient for compact in-vitro diagnostic instruments to make accurate and rapid measurements. This has led to market demands for even higher sensitivity. Combining a photon counting head with lens allows the collection of the target light onto the photosensitive area to increase the amount of incident light and in this way provide higher sensitivity. However, ordinary condenser lenses require a specific distance between the lens and the photosensitive surface which makes the size of compact in-vitro diagnostic instruments large and bulky. To handle this challenge, the company maintained the size of the product all while increasing its sensitivity. 

In addition to applying optical design technology using free-form surfaces, the company collaborated with the Vrije Universiteit Brussels, which has advanced technological capabilities in the field of optics and succeeded in developing a novel lens with a special shape. While ordinary lenses use refraction of incident light to collect light, this newly designed lens uses refraction, reflection and total-internal-reflection of incident light to collect light. This lens also allows the collection of light through different optical paths in the center and at its periphery, making it possible to collect light very efficiently in spite of its thin profile. Moreover, the shape of the lens is optimised to match the shape and characteristics of the PMT and in this way enhance detection efficiency. The lens exhibits an excellent light-collection effect not only for collimated light but also for diffused light which is usually quite difficult to collect.

Installing the H10682-110W into compact in-vitro diagnostic instruments such as chemiluminescence immunoassay analyzers used for blood testing will increase their sensitivity. The newly designed lens also offers good prospects spanning a diverse range of applications including analytical instruments, medical diagnosis, communications, and semiconductors where compact and highly sensitive photodetectors are required.

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