IEC 60747-5-4:2022(E) specifies the terminology, the essential ratings and characteristics as well as the measuring methods of semiconductor lasers.
This edition includes the following significant technical changes with respect to the previous edition:

1. References for the terms and definitions related to the lighting area, IEC 60050-845, are revised based on IEC 60050-845:2020;
2. Emission angle is changed to radiation angle in 3.3.2;
3. Definitions of rise time and fall time in 3.4.1 are revised based on the publication IEC 60050-521:2002;
4. Spectral linewidth is added to Table 1 in Clause 4;
5. Conditions for carrier-to-noise ratio of Table 1 in Clause 4 is amended.
6. Error in the equation for carrier-to-noise ratio in 5.2.2 is corrected;
7. Precaution against the equipment used for carrier-to-noise ratio measurement is added in 5.2.2;
8. Explanation for the measurement method of the small signal cut-off frequency in 5.3.2 of the first edition is deleted because it has been defined in the latest version of ISO 11554;
1. Reference document for the lifetime in 5.4 is amended;
10. Precaution against the measuring arrangement used for the half-intensity width and 1/e2-intensity is added in 5.5.3;
11. Reference tables in Annex A, Annex B and Annex C are revised by following the latest version of ISO publications.