Development of Line-narrowed Diode Pump Sources for DPAL systems

Eotron"s advanced diode laser packaging technology allows construction of an efficient and compact line-narrowed diode stack combined with Volume Brag Grading (VBG) for pumping a Diode Pumped Alkali Laser (DPAL). A single laser diode bar with a 20pm spectral line-width demonstrated more than 30W of cw output power at 780nm pumping a rubidium vapor laser. However, current diode laser stacks have failed to narrow spectral line-widths below 0.05nm due to pointing inaccuracies with the individual diode bars and thermal instability of a large VBG. Eotron"s technology places all laser diode bars in near perfect alignment to the VBG, narrowing spectral line-width. Lowering thermal resistance of the silicon diode package improves electrical-to-optical efficiency, stabilizes turn-on time and wavelength drift of the DPAL system. Also, the cooling technology of Eotron"s Silicon Macro-Channel (SMC) design will be applied to the VBG element to stabilize wavelength drift and local thermal effect. Eotron"s SMC and silicon packaging implemented in diode laser stacking along with VBG cooling, will demonstrate improved performance and spectral line-width narrowing due to its"accurate micron-level assembly of the diode stack, overcoming the limitations of current diode laser technologies to allow the delivery of a cost effective pumping module for DPAL systems.