Reduction of optical crosstalk in silicon photomultipliers

Abstract

The Silicon Photomultiplier (SiPM) is a novel device for low level light detection in various applications, for example scintillator-and fiber readout. 1,2 The SiPM is insensitive to magnetic fields and has a high photon detection efficiency. Current devices have a high optical crosstalk probability, which causes a significant increase of the excess noise factor. 3 It may replace traditional Photo Multiplier Tubes (PMT) when the optical crosstalk is reduced to a lower level of below 10%.Depending on the quantity of hot electrons in the Geiger discharge approximately three to fifty secondary photons (in average three photons per 10 5 avalanche electrons 4 ) with a wavelength range from 450nm to 1600nm are emitted from the excited cell in all directions. 5 Some of those secondary photons cause the discharge of the neighboring cell. 6,7 The different mechanism of optical crosstalk are categorized as direct and indirect crosstalk.To reduce direct crosstalk an optical barrier has to be implemented between the single micro cells. 8 Thus, we have investigated different technological concepts with regard to the trench shape, the trench etching process as well as the trench fill material.

Avalanche Photodiodes and Silicon Photomultipliers of Non-Planar Designs

“…Thus, planar SiPM by MEPhI/Pulsar and CPTA substituted non-planar MRS APD because of higher PDE, lower DCR, lower optical crosstalk, and more reliable production and operation. Since the mid 2000s, planar SiPM has been globally recognized as a new photon-number-resolving avalanche detector of outstanding performance, and the planar SiPM modifications were developed by Hamamatsu [ 38 ], SensL [ 39 ], ST Microelectronics [ 40 ], FBK [ 41 ], Excelitas Technologies [ 42 ], and KETEK [ 43 ] with various combinations of pixel separation by guard rings and trenches.…”

The Eu Optional Instrument: Absorbing the Private International Law Implications of a Common European Sales Law

“…Furthermore, since the directive is designed to protect only consumers, a guarantee comes within the scope of the directive only where, in accordance with the first indent of Article 2, the guarantor has entered into a commitment for a purpose which can be regarded as unconnected with his trade or profession." 94 In reaching this conclusion, which gives a glimpse of how the CJEU might approach this issue in the context of the Unfair Terms Directive, 95 the European Court of Justice noted that nothing in the Doorstep Selling Directive required "the person concluding the contract under which goods or services are to be supplied be the person to whom they are supplied" 96 and that surety agreements are merely ancillary to the main contract. 97 Returning to the case law in England and Wales, in Barclays Bank Plc v. Kufner 98 Field J., relying heavily on the Opinion of the European Court of Justice in Bayerische Hypothetken-und Wechselbank v. Dietzinger 99 -held that surety transactions are not excluded from the scope of the Regulations.…”

“…94 In reaching this conclusion, which gives a glimpse of how the CJEU might approach this issue in the context of the Unfair Terms Directive, 95 the European Court of Justice noted that nothing in the Doorstep Selling Directive required "the person concluding the contract under which goods or services are to be supplied be the person to whom they are supplied" 96 and that surety agreements are merely ancillary to the main contract. 97 Returning to the case law in England and Wales, in Barclays Bank Plc v. Kufner 98 Field J., relying heavily on the Opinion of the European Court of Justice in Bayerische Hypothetken-und Wechselbank v. Dietzinger 99 -held that surety transactions are not excluded from the scope of the Regulations. 100 By contrast in Bank of Scotland v. Singh 101 Judge Kershaw QC, apparently operating closer to the actual wording of the Regulations, held that the Regulations did not apply to surety transactions and his view has subsequently been described as "compelling" 102 and "convincing".…”