L-band erbium-doped fiber laser with coupling-ratio controlled wavelength tunability

Abstract

By controlling the output coupling ratio, we demonstrate a novel wavelength-tunable L-band Erbium-doped fiber laser (EDFL) with a maximum tuning range up to 58 nm (from 1567 to 1625 nm) by controlling its output coupling ratio between 1% and 99%. The L-band EDFL is configured by using a bi-directionally dual-wavelength pumped EDFA in close-loop with an output coupler of tunable coupling ratio and an air-gap inserted FC/PC connector pair. Such an EDFL exhibits a quantum efficiency of 42% and an ultra-high power conversion efficiency of 37% under optimized pumping scheme, providing the small-signal gain and output power of ~34 dB and 91 mW, respectively. Low variation of <1.2 dB on channel power, power fluctuation of 0.04% and a narrow linewidth of 0.03 nm are obtained.

16 μm emission based on linear loss control in a Er:Yb doped double-clad fiber laser

“…A large tunable spectral range covering the (C L)-band has been demonstrated in [6], with a C-band amplifier using an intracavity spectral filter and a control of the cavity losses, which have to be low. A variable output coupler has been used in [7], leading to a large wavelength tunable range without spectral filtering. Previous works [5][6][7] concerned CW operation, and the output power above 1.6 μm remained below 20 mW.…”

Compact Widely Tunable C- Plus L-Band Erbium-Doped Laser and Amplifier

“…1, a tunable bandpass filter (TBF) is inserted in the cavity to eliminate the amplified spontaneously fluorescence emission to oscillate in the cavity and then to increase the SNR of the laser output. The wavelength tunability of an EDFL can be greatly affected by several cavity parameters such as the intra-cavity loss, the output coupling ratio (or reflectivity), and the active fiber length [14]. A deeply saturated EDFA under high-power feedback injection has shown the capability to offer wide-band and flat gain, and the L-band EDFL can be readily available by minimizing the intra-cavity loss to keep largest gain in the EDFL cavity.…”

“…Typically, the gain media such as the erbium-doped fiber (EDF) and the erbiumytterbium codoped double clad fiber [7], were employed to configure the L-band EDFLs in dual resonant cavity [8], linear overlapping cavity [9], and single ring cavity [10]. Different approaches for wavelength-tuning the EDFL with the intra-cavity Fabry-Perot filters [11], the fiber Bragg gratings (FBGs) [12,13] and the tunable-ratio optical coupler [14] were proposed.…”

Linewidth characteristics of a filterless tunable erbium doped fiber ring laser

“…13 The reduction in linewidth due to the inclusion of an air gap in the cavity is reported for a filterless laser with coupling ratio controlled wavelength tunability. 11 However, in the case of filterless lasers, the lasing wavelength depends dynamically on the cavity parameters, and the linewidth characteristics of such lasers are not discussed in any of the previous works to the best of our knowledge. Since filterless lasers are competent enough for most of the applications requiring tunable lasers, it is important to study the linewidth characteristics of a͒ Author to whom correspondence should be addressed.…”

“…10 Lin and co-workers recently demonstrated a coupling ratio controlled wavelength tunable erbium doped fiber ring laser ͑EDFRL͒ using both 980 and 1480 nm pumpings and achieved continuous tuning from 1567 to 1612 nm. 11,12 The linewidth of the output of a tunable laser is usually decided by the spectral characteristics of the filter used. Hence, for practical applications, the design of the filter is improved to improve the linewidth of the laser.…”