This part of IEC 62149 covers the performance specification for optical modulators monolithically integrated with laser diodes for 2,5 Gbit/s to 40 Gbit/s multi-channel fibre optic transmission systems. This performance standard contains a definition of the product performance requirements together with a series of sets of tests and measurements with clearly defined conditions, severities and pass/fail criteria. The tests are intended to be run as an initial design verification to prove any product’s ability to satisfy the performance standard’s requirements. This standard is only applicable for on-off keying format. A product that has been shown to meet all the requirements of a performance standard can be declared as complying with the performance standard, but should then be controlled by a quality assurance program.