Photonics Research, Volume. 8, Issue 7, 1100(2020)
Widely tunable ultra-narrow-linewidth dissipative soliton generation at the telecom band
Fig. 1. Schematic diagram of the widely tunable ultra-narrow-linewidth passively mode-locked erbium fiber laser. LD, laser diode; WDM, wavelength division multiplexer; EDF, erbium-doped fiber; TBF, tunable bandpass filter; SESAM, semiconductor saturable absorber mirror; PC, polarization controller.
Fig. 2. Characterization of the laser output. (a) Oscilloscope trace, (b) intensity autocorrelation. Note that the width of the autocorrelation trace is larger than the actual pulse width by a factor of 1.54 for
Fig. 3. Numerical modeling of mode-locked laser pulses. (a) Temporal pulse profiles and (b) pulse spectra at three different small-signal gain coefficients (11.7 dB for red, 12.5 dB for green, and 13.2 dB for blue); (c)–(f) calculated pulse parameters, (c) pulse width, (d) linewidth, (e) time–bandwidth product (TBP), and (f) pulse energy over a range of small-signal gain coefficient values. The three vertical arrows in (c) indicate the small-signal gain coefficients that correspond to the curves of respective colors in (a) and (b). The laser wavelength is fixed at 1550 nm for all calculations.
Fig. 4. Theoretical analysis of our ultra-narrow-linewidth dissipative soliton fiber laser. (a)–(d) Intracavity evolution of the pulse parameters: (a) pulse width, (b) linewidth, (c) time–bandwidth product (TBP), (d) pulse energy. F, bandpass filter; EDF, erbium-doped fiber; O, 50/50 output coupler; S, saturable absorber; A, attenuator. (e) Calculated pulse widths over a varying SESAM modulation depth for five different intracavity filter bandwidths (0.09, 0.11, 0.13, 0.17, and 0.23 nm). The gray region indicates where the stationary single-pulse solution does not exist. The small-signal gain coefficient is fixed at
Fig. 5. Dependence of pulse parameters on the delay line length measured over a range of pump power values. (a)–(d) Measured pulse parameters, (a) pulse width, (b) linewidth, (c) time–bandwidth product (TBP), and (d) pulse energy for six different lengths of standard single-mode fiber (SMF) delay line (40, 50, 60, 70, 80, and 140 m), which yield net cavity dispersions of 1.1, 1.3, 1.5, 1.7, 1.8, and 2.8 ps/nm, respectively. (e)–(h) Measured pulse parameters, (e) pulse width, (f) linewidth, (g) TBP, and (h) pulse energy for six different lengths of non-zero dispersion-shifted fiber (NZDSF) delay line (40, 50, 60, 70, 80, and 140 m), which yield net cavity dispersions of 0.16, 0.11, 0.065, 0.013,
Fig. 6. Characteristics of laser wavelength tuning. (a) Normalized optical output spectra of the laser with an 80-m-long single-mode fiber (SMF) delay line obtained by a grating-based optical spectrum analyzer (OSA). The laser wavelength can be tuned without pulse breakup over a 34.3 nm range (1529.3–1563.6 nm) by changing the center wavelength of the intracavity tunable bandpass filter and the pump power. (b)–(e) Pump power dependence of pulse parameters, (b) pulse width, (c) linewidth, (d) time–bandwidth product (TBP), and (e) pulse energy measured at six different laser wavelengths. (f) Normalized optical output spectra of the laser with an 80-m-long non-zero dispersion-shifted fiber (NZDSF) delay line obtained by a grating-based OSA. The laser wavelength can be tuned without pulse breakup over a 33.4 nm range (1529.7–1563.1 nm). (g)–(j) Pump power dependence of pulse parameters, (g) pulse width, (h) linewidth, (i) TBP, and (j) pulse energy measured at six different laser wavelengths. The colored numbers in (b) and (g) indicate the laser wavelengths in nm, which correspond to the colors of the laser spectra in (a) and (e), respectively. The laser spectra in black in (a) and (f) are obtained close to the lower and upper bounds of the wavelength tuning range.
Fig. 7. Characteristics of the laser noise. (a) Timing jitter power spectrum, (b) integrated timing jitter, (c) relative intensity noise (RIN) power spectrum, (d) integrated RIN. In all measurements, we fix the pump power as 265.2 mW, the single-mode fiber delay line length as 80 m, and the laser wavelength as 1550 nm. PSD, power spectral density.
Get Citation
Copy Citation Text
Chang Kyun Ha, Ki Sang Lee, Dohyeon Kwon, Myeong Soo Kang. Widely tunable ultra-narrow-linewidth dissipative soliton generation at the telecom band[J]. Photonics Research, 2020, 8(7): 1100
Category: Lasers and Laser Optics
Received: Jan. 24, 2020
Accepted: Mar. 30, 2020
Published Online: Jun. 3, 2020
The Author Email: Myeong Soo Kang (mskang@kaist.ac.kr)