Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator

Abstract

In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal–oxide–semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single sideband (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.

Utilizing dual-pass composite-ring architecture for a stabilized and wavelength-selectable single-longitudinal-mode erbium-doped fiber laser

“…As shown in figure 2, nearly 15 dB power difference of ASE can be obtained in the wavelengths from 1530-1560 nm due to the EDF characteristic. This would also produce the gain competition and larger power difference of the lasing wavelength in the EDFbased laser [2]. The inset of figure 2 is the measured output spectrum of the TBF with Gaussian-shaped in the wavelength of 1550 nm.…”

“…Over the past decade, the stable and wavelength-tunable erbium-doped fiber (EDF) laser has attracted much research interest due to its potential applications, such as optical fiber sensors, dense wavelength division multiplexing communication, and optical instrument testing [1]. Commonly, the EDF laser also has the possibility of a multi-longitudinal mode (MLM) with mode-hopping and homogeneous broadening effects due to a longer cavity length and very narrow longitudinal-mode spacing [2,3]. In order to accomplish a singlelongitudinal mode (SLM) in an EDF laser, several filtering technologies have been proposed, such as utilizing an EDFbased saturation absorber filter [4], using a multi-ring filter [3], employing a self-injection method [5], and an optical birefringent filter [6].…”

Linewidth depth narrowing and control of linear cavity fiber laser based on distributed external feedback

“…Since the advent of lasers, ultra-narrow linewidth fiber lasers with high coherence have been widely used in signal synthesis, optical precision metrology, medical diagnosis and other fields [1][2][3] , so they have attracted extensive research interests. It is worth mentioning that a fiber laser with controllable linewidth can be adapted to different application scenarios, such as secure optical communication, wavelength division multiplexing and optical sensing to improve their parameter performance [4][5][6] .…”

Wavelength-tunable single-frequency ytterbium-doped fiber laser based on a double-circulator interferometer

“…Many more components, such as a π-phase shifted fiber Bragg grating, a nonlinear semiconductor optical amplifier or a high finesse fiber ring filter can be inserted into the ring cavity to obtain SF oscillation [10][11][12]. Besides, some novel structures relying on the Vernier effect, such as multi-rings [13], 'eye-type' triple-ring, a double-ring fiber cavity with microspheres as the mode selector and microresonators [14], have all been employed to achieve SF operation in the ring cavity [13][14][15][16]. Especially, the combination of a dynamically induced grating formed in the unpumped rare earth doped fiber (Er-doped and Yb-doped) and a Sagnac loop have attracted considerable attention since this configuration does not limit the lasing wavelength in the cavity [17,18] and can serve as a key tool of achieving tunable wavelength lasing [19,20].…”