Pulsed fiber lasers have displaced roughly 70% of the LPSS and DPSS lasers traditionally used in basic marking applications, but have seen limited success at displacing DPSS lasers in high finesse applications. Multiwave’s new MOPA-M-HP laser is poised to change that, enabling the use of pulsed fiber lasers in the most demanding applications while making new applications possible at a much reduced cost.
Pulsed DPSS lasers have been serving high finesse applications in the Semiconductor and Microelectronics markets for many years, and one of the key reasons is the excellent beam quality to achieve tightly focused spot sizes and controlled depth of focus in applications such as resistor trimming, DRAM repair, microstructuring, micromachining and ceramic and thin film scribing. In parallel, high peak powers and good stability are also important characteristics for these applications, and high finesse DPSS also provide them.
Up until now, the combination of beam quality, high peak power and high stability from available pulsed fiber lasers was marginally acceptable for these applications. Multiwave’s new MOPA-M-HP series pulsed fiber lasers not only match the beam quality of DPSS lasers (M2 ~1.2) but maintains this beam quality over all operation conditions, including over a pulse repetition frequency range from single shot (at maximum peak power) to over 500 kHz, an output power range to over 20 Watts, a pulse peak power up to 12 kW and/or over a pulse width range that extends from 10 to 200 ns. In addition, warm-up time is nearly zero, the lasers emit no residual lasing in between pulses and all pulse parameters can be controlled and changed on-the-fly via a built-in digital interface. In addition, for processing heat sensitive materials the laser allows for longer pulses, say 200 ns, to be replaced by bursts of shorter pulses closely spaced (say a burst of five 10 ns pulses spaced by 50 ns, or at 20 MHz).
The inherent thermal loading issues faced by DPSS lasers limit the operating range for which they can ensure a good beam quality. Properly designed fiber lasers such as Multiwave´s new MOPA-M-HP series are immune to these thermally induced restrictions, and takes the advantage over high finesse DPSS lasers several steps further to offer a level of performance and flexibility that exceeds high finesse DPSS lasers at a cost 3 to 4 times less.