Nature photonics highlight dark lasers!

Han Zhang, Dingyuan Tang, Luming Zhao and Wu Xuan,“Dark pulse emission of a fiber laser’’ Physical Review A, 80, 045803 (2009). [Full-text PDF]


Dark laser debut

Phys. Rev. A 80, 045803 (2009)

Although lasers are well known to emit bright pulses of light, a team of researchers in Singapore have now demonstrated the exact opposite — a fibre laser that emits a stream of 'dark pulses'. The erbium-doped fibre laser developed by Han Zhang and co-workers from Nanyang Technological University emits a series of intensity dips in a continuous-wave background of laser emission. The scientists attribute the phenomenon to dark-soliton shaping in the laser cavity. The laser consists of a fibre ring cavity that contains a 5 m length of erbium-doped fibre to provide optical gain and a 150 m length of dispersion compensation fibre. It also features a polarization controller, an isolator, a 50:50 output coupler and a multiplexer for injecting 1,480 nm pump light into the cavity. The researchers observed a series of dark pulses at the fundamental cavity repetition rate. They also say that by carefully controlling the pump strength and orientation of the polarization controller, the output could be reduced to a single dark pulse. Analysis suggests that the dark pulses have a hyperbolic-tangent profile and a typical pulse width of 8 ps, and are transform-limited.

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer