24-line multiwavelength operation of erbium-doped fiber-ring laser

TLDR

The laser achieves 24‑wavelength operation using a low‑loss cavity with controlled polarization evolution and liquid‑nitrogen cooling to enhance spectral and polarization hole‑burning, without any wavelength‑selective components, and the comb spectrum can be tuned by adjusting cavity elements. The laser simultaneously emits up to 24 wavelengths with less than 3 dB amplitude variation across a 17‑nm band, a 0.15‑nm linewidth, 1.1‑nm spacing, and SNR exceeding 30 dB over most of the erbium bandwidth.

Abstract

Simultaneous lasing at up to 24 wavelengths is demonstrated in an erbium-doped fiber-ring laser using a simple design. This result is achieved using a low-loss cavity, controlled polarization evolution and liquid nitrogen cooling to enhance spectral hole-burning, polarization hole-burning, and polarization selectivity. The design does not include any wavelength-selective components; instead, it utilizes wavelength selectivity provided by polarization evolution in the cavity. The amplitude variation between emission peaks is less than 3 dB over a 17-nm spectral range. A narrow linewidth of 0.15 nm, dense line spacing of 1.1 nm, and a good signal-to-noise ratio of more than 30 dB are achieved over most of the erbium bandwidth. The comb spectrum location and width are adjustable by changing and adjusting cavity components.