Photon frequency doubler is controlled by light – Physics World
Second-harmonic generation - Wikipedia
Non-locality and collective emission in disordered lasing resonators | Light: Science & Applications
Frequency-doubled diode-pumped disk lasers | Jenoptik
Resonant frequency doubling of few-frequency fiber laser is path to high power output | Laser Focus World
Intracavity frequency doubling, explained by RP Photonics Encyclopedia; second-harmonic generation, nonlinear frequency conversion, SHG, doubler crystal, green problem
All-solid-state continuous-wave frequency-doubled Nd:YAG–BiBO laser with 2.8-W output power at 473 nm