| In force components | 
| Number 
 | Title | Status | 
| G.661 (05/25) 
 | Definitions and test methods for the relevant generic parameters of optical amplifier devices and subsystems | In force (prepublished) 
 | 
| 
 | 
| Superseded and Withdrawn components | 
| Number 
 | Title | Status | 
| G.661 (03/93) 
 | Definition and test methods for the relevant generic parameters of optical fibre amplifiers | Superseded 
 | 
| G.661 (11/96) 
 | Definition and test methods for the relevant generic parameters of optical fibre amplifiers | Superseded 
 | 
| G.661 (10/98) 
 | Definition and test methods for the relevant generic parameters of optical amplifier devices and subsystems | Superseded 
 | 
| G.661 (03/06) 
 | Definition and test methods for the relevant generic parameters of optical amplifier devices and subsystems 
 | Superseded 
 | 
| G.661 (07/07) 
 | Definitions and test methods for the relevant generic parameters of optical amplifier devices and subsystems | Superseded 
 |