IEC TR 62627-08:2016,Fibre optic interconnecting devices and passive components – Part 08: Study of optical power blocking measurement methods for adaptors with an optical power blocking shutter.
In recent years, optical communication networks have made greater use of optical fibre amplifiers and distributed Raman amplifiers. Optical communication equipment usually has an adaptor on the front of the board as an optical input/output terminal. These adaptors sometimes emit 100 mW or higher optical power. For the purpose of blocking such optical power, an adaptor with an optical power blocking shutter is sometimes used.
This Technical Report details the proposed methods to evaluate the efficacy of these adaptor shutters.
This Technical Report is based on Optoelectronic Industry and Technology Development Association (OITDA) — Technical Paper (TP), TP19/CN-2014, Investigation of examinations and measurements — Light-blocking performance of optical adaptor with shutter.
This part of IEC 62627, which is a Technical Report, describes two methods used to measure the blocking characteristics of adaptors with an optical power blocking shutter. This document focuses on singlemode fibre (SMF) and two wavelengths, 1 310 nm and 1 550 nm.
4 Background to the measurement method of blocking characteristics for adaptors with an optical power blocking shutter
4.1 Laser safety requirement for optical fibre communication systems
The safety of laser products are defined in IEC 60825-1 which prescribes the acceptable optical power as the laser safety class. IEC 60825-2, a subdivision standard, provides the safety standards for optical fibre communication systems. Optical communication equipment
manufacturers sometimes use an adaptor with an optical power blocking shutter to comply with these laser safety standards.
4.2 Required performance of the power blocking shutter
IEC 60825-2, hazard level 3B, limits optical power at 1 550 nm to 500 mW. However, hazard level 1, the optical power allowed to be seen by the naked eye or with a magnifying scope, is limited to 10,2 mW. If equipment manufacturers ensure laser safety only by using an adaptor with an optical power blocking shutter, the required level of optical power blocking for the shutter is 17 dB, i.e. the ratio of 500 mW to 10,2 mW.
4.3 Standard measurement conditions used to determine laser safety for optical fibre communication systems
IEC 60825-2 defines the measurement conditions used to determine the hazard level of optical fibre communication systems. For wavelengths greater than 1 400 nm, an aperture diameter of 7 mm is used at a measurement distance of 28 mm from the radiating end of the optical fibre. For wavelengths less than or equal to 1 400 nm, the aperture diameter is also 7 mm, but the measurement distance is 70 mm from the radiating end of the optical fibre.IEC TR 62627-08:2016 pdf download.