A diode-pumped 1.5 μm waveguide laser mode-locked at 6.8 GHz by a quantum dot SESAM

Abstract

Abstract. We report a passively mode-locked, diode-pumped waveguide laser operating in the 1.5 m spectral region using a quantum dot SESAM as the saturable absorber element. A repetition rate of up to 6.8 GHz and an average power as high as 30 mW is obtained during mode-locked operation. Minimum pulse duration of 2.5 ps is produced at a wavelength of 1556 nm. The repetition rate of the source was tuned by more than 1 MHz by changing the pump power, demonstrating a possible route towards integrated pulse repetition rate stabilisation.

Graphene Q-Switched Mode-Locked and Q-Switched Ion-Exchanged Waveguide Lasers

“…The output power against incident power for both the waveguides using different OCs is shown in figure 2. From the measured slope efficiencies the losses are estimated to be <0.5 dB/cm in agreement with previously fabricated ion-exchanged waveguides [9][10][11].…”

“…Indeed, mode-locked waveguide lasers have been demonstrated using SESAMs [9][10][11][12], obtaining a repetition rate as high as 15 GHz [10] from an integrated ion-exchanged waveguide laser. Ionexchange is a versatile technique for producing low-loss waveguides and is compatible with photonic mass-production techniques.…”

Graphene Q-switched mode-locked waveguide laser operating at 1535 nm

“…The RF spectrum was found to be centred at 6.8 GHz and is shown in figure 2 (a). The peak at 6.8 GHz is broad when compared to a CW mode-locked waveguide laser [3], which is expected for Q-switched mode-locked pulses [5,9]. The output from the fast detector was then connected to a 50 GHz scope and the measured train of pulses contained within the Q-switched envelope is shown in figure 2 (a).…”

“…Other advantages include a low laser and mode-locking threshold owing to the small mode sizes and a thin-slab configuration allowing good thermal management which is advantageous for power scaling. Recently, several mode-locked waveguide laser systems have been demonstrated [1][2][3] in the 1-1.5 m spectral window using semiconductor saturable absorber mirrors (SESAMs) with repetition rates as high as 15 GHz [2] being achieved. However, SESAM fabrication can be relatively expensive and the resulting bandwidth of operation of the device is quite limited. Graphene has recently emerged as an interesting alternative for use as a saturable absorber [4] and has the advantage of having a wide wavelength band of operation and being easy and relatively low-cost to fabricate.…”

456-mW graphene Q-switched Yb:yttria waveguide laser by evanescent-field interaction

“…Waveguide lasers offer interesting advantages for such systems including monolithic integrated structures with a natural compatibility with the geometry of high-power diode pump lasers allowing compact devices [4,5]. Additionally, if propagation losses can be kept low, optical confinement can lead to low laser thresholds, high efficiencies, and low power requirements for passive Q-switching [4][5][6][7] or mode-locking [8,9] via saturable absorbers (SAs).…”