IEC 61300-2-40 pdf download.Fibre optic interconnecting devices and passive components – Basic test and measurement procedures
1 .1 Scope and object This part of IEC 61 300 describes the test for screening single-mode tuned connectors against tuning errors. It is applicable to single-mode angled connectors which are equipped with a tuning mechanism. The tests ensure that the plugs passing this test have attenuations lower than A max when they are randomly mated to other connectors of the same type. 1 .2 General description Attenuation is mainly caused by lateral misalignment of the respective fibre cores. The misalignment is related to the lateral offsets of the fibre core centre to the ferrule axis of each connector plug. In order to tune a connector, the plug shall have a lateral fibre core offset located in a specified adjusting sector. The screen test method described in the subsequent procedure is able to identify plugs having the desired performance. 1 .3 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 61 300. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of IEC 61 300 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 61 300-3-4, Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 3-4: Examination and measurements – Attenuation 1 .4 Adjusting sector Each connector based on a “plug/adaptor/plug” structure defines an (Oy) axis around which the two plugs are in a symmetrical position.
2.1 Optical source (S) Unless stated otherwise in the test procedure, the recommended source is a laser diode. 2.2 Excitation unit (E) Unless stated otherwise in the test procedure, the excitation unit is only a single mode fibre length greater than 2 m. 2.3 Detector (D) Unless stated otherwise in the test procedure, the recommended detector is a large sensitive area. 2.4 Temporary joints (TJ) 2.5 Screen plug for tuned connector (SP) This is an angled polished plug which has a lateral offset of the fibre core eccentrically positioned at a theoretical true position, with a tolerance from this theoretical true position. This reference plug shall be defined in the relevant connector specification. The preferred true position is located at 0,75 µm from the ferrule axis, in the direction of the adjusting axis. The fibre core is within 0,3 µm around this true position (see figure 1 ). In order to reduce dispersion in attenuation due to the mode field diameter difference the screen plug should use the same fibre type as the plug to be screened. 2.6 Reference adaptor (RA) The reference adaptor shall be defined in the connector detail or product specification.
Preconditioning procedure: The alignment and end surfaces of the plug ferrules and the adaptors shall be cleaned before test. The clean conditions shall be maintained during the test. The attenuation measurement methods shall comply with IEC 61 300-3-4, Insertion method B, and shall be conducted at ambient temperature. No recovery procedures are required. The attenuation limit A ref for screening the plug under test depends on the connector construction. Measure the attenuation A o of the plug under test with a reference adaptor (RA) and a screen plug (SP). A o has to be smaller than a specific value A ref . The relation between the maximum attenuation in random mating A max that is expected for screened plugs and A ref shall be defined in the connector detail or product specification. If not, A ref has to be specified in the test procedure.