English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We have specifically investigated the free-space mode locking dynamics oferbium-doped fiber (EDF) mode-locked ultrafast lasers via nonlinearpolarization rotation (NPR) in the normal dispersion regime. To do so, we builta passively mode-locked fiber laser based on NPR with a repetition rate of 89MHz producing an octave-spanning spectrum due to supercontinuum (SC) generationin highly nonlinear fiber (HNLF). Most significantly, we have achieved highlystable self-starting NPR mode-locked femtosecond fiber laser based frequencycomb which has been running mode locked for the past one year without any needto redo the mode locking. By using the free-space NPR comb scheme, we have notonly shortened the cavity length, but also have obtained 5 to 10 times higheroutput power (more than 30 mW at central wavelength of 1570 nm) and muchbroader spectral comb bandwidth (about 54 nm) compared to conventionalall-fiber cavity structure with less than 1 mW average output power and only 10nm spectral bandwidth. The pulse output from the NPR comb is amplified througha 1 m long EDF, then compressed by a length of anomalous dispersion fiber to anear transform limited pulse duration. The amplified transform limited pulse,with an average power of 180 mW and pulse duration of 70 fs, is used togenerate a supercontinuum of 140 mW. SC generation via propagation in HNLF isoptimized for specific polling period and heating temperature of PPLN crystalfor SHG around 1030 nm.

Free-space NPR mode locked erbrium doped fiber laser based frequency comb for optical frequency measurement