frequency limitation TTL

on drivers often write frequency TTL. Example 30 or 50 kHz. But what does it mean? This frequency limit? Than it is limited?

Such as laser printers or fiber lasers TTL frequency can reach megahertz. However, the driver there assembled on special chips.

It means the driver cannot respond to or replicate signals faster than the limit. It doesn't mean the diode can't, just the driver can't.

It is a driver limitation indeed. The actual diode can handle signals much, much faster. Just think about how fast a dvd writer diode would need to be switched on and off when recording megabytes a second.

The figure quoted usually is a guarantee though, and doesnt mean that the driver cannot actually switch faster than 30 or 50 kHz. These speeds just coincide with how fast you can move galvo mirrors, which is often the limiting factor in what you can project.

DPSS lasers are an exception however: due to their nature they just don't switch on and off very quickly, regardless of how fast the driver can turn the current through the pump diode on and off.