Youopto 14pin butterfly narrow linewidth laser is a single wavelength semiconductor laser independently developed and produced by Youopto. It adopts high-performance DFB chip and domestic leading butterfly  packaging technology, with built-in cooler, thermistor, monitoring photodiode and optical isolator (optional). The laser can work normally under different ambient temperatures, and the output wavelength and optical power are highly stable. Wavelength: 1550nm (optional for C and L bands).