Alternate cooling and use schemes for low SWaP fiber pump modules (Conference Presentation)

Recent developments in fiber lasers show the field has reached a high level of maturity, and several demonstration programs have shown successful scaling of output power into the 30-50kW regime while maintaining good beam quality. Despite these successes, much work remains before fibers lasers are ready for the range of field applications currently envisioned. Constraints set by small system size, limited power availability, and harsh environmental conditions demand that novel modes of operation be considered. The variety of use conditions for which high power fiber lasers are being considered poses additional challenges to the system architect, and the full trade-space is not yet clear. In advance of full system definition, Coherent|DILAS has continued to develop technologies that will extend the trade-space available to the system designer and facilitate transition to the field. We will report on a variety of efforts to extend the use range of existing, SWaP optimized fiber pump modules into territory appropriate for the more demanding of these applications. Of particular concern are the system cooling architectures needed to support diode pump modules, which in the case of large systems, comprise a significant size and power demand. While efforts to improve SWaP of cooling systems generally have negative effects on diode performance, here we show that negative effects resulting from coolant system design can be mitigated. Operational results that pair existing lightweight, high power modules with non-standard cooling architectures, pulse schemes, and wavelength stabilization will be discussed.