Opto-pyrotechnic systems are in widespread use in both launchers and satellites. Intense laser pulses are distributed via optical fibers to activate specific events through controlled explosions. Among the operations triggered by ignition wavelength are the ignition of engines, of boosters and of distancing rockets. Opto-pyrotechnics are also used for stage and payload separation, valve opening, passivation and, if required, neutralization of the launcher. Some launchers can include several hundreds of meters of opto-pyrolines and several tens of pyro-functions.

Opto-Pyrotechnics, i.e., initiation by laser pulses, has several advantages:

• no primary explosives are required (use of comparably insensitive secondary explosives increases safety)
• the devices are light and compact
• the devices provide near-instantaneous response
• reduced total mass
• possible new functionality (built-in system test/verification)
• low current requirements
• potential for better safety (immunity to EMI and ESD).

Although the system has been proven to be both reliable and safe, it is difficult to verify the integrity of the opto-pyrolines.

In order to detect in a safe way a default on the opto-pyrotechnic train line, such as a failure transmission or a weak connection, SEDI-ATI has developed a customizable multimode wavelength division multiplexer [WDM] with specific properties to address this type of application.

The materials are selected with care: very low outgassing, lightweight, space qualified… Therefore, this ruggedized WDM performs its required security-check function under operational conditions of temperature, altitude, vacuum, radiation… Also, its performances of are not affected by acceleration forces, nor by shocks and vibration levels encountered during handling, transportation and launch operations.