Highly efficient watt-level single frequency 461 nm laser

High power single-frequency 461 nm laser are useful for many areas of physics involving strontium atoms such as laser cooling and manipulation [1] or quantum information transfer [2] . For these applications, a few hundreds of mW is required. Among all the different approaches to generate blue light such as laser diodes or single-pass second-harmonic generation (SHG) with a crystal, SHG generation exploiting a resonant cavity is the only technique allowing to obtain this level of power with high efficiency. However, this type of architecture requires complex alignment and is very sensitive to external vibrations. We have developed an ultra-compact linear cavity glued to a zerodur plate to overcome these difficulties.