Nanosecond Laser Module for DTS
Distributed temperature sensing systems (DTS) often require nanosecond pulsed lasers for improved spatial resolution, with typical values capable of outputting lasers with 10 ns pulse widths and 10k re-frequencies.
Pulse width 10ns, repetition frequency 10KHz
Distributed fiber optic temperature measurement systems typically require a high spatial resolution, such as the common 1 meter spatial resolution. To achieve a spatial resolution of 1 meter, the system's laser needs a pulse width of 10 ns. So in some distributed temperature sensing system with a length of 5km or less, we will use 10ns pulse width and 10KHz heavy frequency rate for sampling.
signal synchronization
Our lasers have SMA signal synchronization interface, you can choose external trigger mode or internal trigger mode when you place an order. When selecting external trigger, TTL signal needs to be input into the laser, then the laser will output light; when selecting internal trigger mode, the laser will synchronize the output of TTL signal, and you can connect this output TTL signal to the acquisition card.The high level of TTL signal is 5V, and the low level is 0V.
62.5/125 multimode fiber
The laser we can choose 62.5/125 or 50/125 fiber. In the distributed temperature measurement system 62.5/125 fiber is used more, because 62.5/125 multimode fiber has better temperature response.
APC or ACC mode
The laser has feedback power control (APC) and current power control (ACC) two modes, in debugging you can first use the ACC mode to modulate the current value, when adjusted to the appropriate value after switching to the corresponding APC mode. The APC mode will be more stable in the production environment.
Pulse width of DTS lasers
The pulse width of the DTS laser can be set through the laser control software, it should be noted that we set the electrical pulse width and not the optical pulse width. The optical pulse width is half the value of the electrical pulse width, i.e. if you set 20ns, the corresponding optical pulse width is 10ns.
The laser is customized for distributed fiber optic temperature measurement applications and features high stability, adjustable pulse width and high peak power output at 1550 nm with a minimum pulse width of 5 ns. It supports both ACC and APC mode operation.