A visible rainbow of hues in a near-infrared (NIR) continuous-wave Raman fiber laser, formed due to 2nd- and 3rd-harmonic conversion of the cascaded IR Stokes wavelengths traveling in the core of the fiber. The laser is pumped only by NIR sources and there is no visible light input. Image captured in the high-power lasers lab in CeNSE, IISc, using a standard DSLR camera with a 30-second exposure.
—Santosh Aparanji, Centre for Nano Science and Engineering, Indian Institute of Science, Bengaluru, India
28 Jan 2022