High-performance 10 GHz all-active monolithic modelocked semiconductor lasers

Long All-Active Monolithic Mode-Locked Lasers With Surface-Etched Bragg Gratings

“…4) and typical 3-dB widths ranged between 3.7 and 6 ps, depending on bias conditions, with time-bandwidth products of 0.4-0.5 (with 6.3 ps/nm added linear dispersion in single-mode fiber). The uncompressed pulsewidths from the FP laser were measured to be 2 ps in accordance with our earlier reported FP laser results [9]. The spectra of the FP laser show the same broad high-energy tail as many other reported monolithic FP MLLs based on quantum wells [9], [10].…”

“…The uncompressed pulsewidths from the FP laser were measured to be 2 ps in accordance with our earlier reported FP laser results [9]. The spectra of the FP laser show the same broad high-energy tail as many other reported monolithic FP MLLs based on quantum wells [9], [10]. Thus, for a fair comparison of the time-bandwidth product, we have chosen the widths instead of the more common half-maximum widths.…”

High-Power and Low-Noise 10-GHz All-Active Monolithic Mode-Locked Lasers with Surface Etched Bragg Grating

“…No major change in pulse width or spectral width could be observed with the addition of the RF-signal, indicating that the filter limits the pulse shortening. By further process optimisation it's possible to achieve a wider filter and thereby shorter pulses [9]. The RFspectrum becomes much narrower in hybrid operation, indicating a good lock to the modulating synthesizer signal.…”

Observation of phase noise reduction in photonically synthesized sub-THz signals using a passively mode-locked laser diode and highly selective optical filtering

“…The passive mode-locked device is completely functional with a DC current signal for the gain section and a DC voltage for the SA region, without the need of a RF reference or any additional external device. Moreover, the phase noise performance in this mode of operation can be extremely good, reaching sub-kHz RF linewidth in the electrical signal associated with the mode-locking repetition rate [11,12]. Alternatively, under active mode-locking operation, the optical pulses are synchronized to an external RF reference at the mode-locked frequency of the device (or subharmonics).…”

“…Longitudinal confinement of the optical field is achieved by the formation of a 2 µm width ridge waveguide structure. The facet at the absorber end is HR coated (95% reflection) and the output facet is as cleaved [11]. The operation point of the device has been chosen to be within the mode-locking region of the dynamics map of the device.…”