Abstract
We report on the characterization of the timing stability of passively mode-locked discrete mode diode laser sources. These are edge-emitting devices with a spatially varying refractive index profile for spectral filtering. Two devices with a mode-locking frequency of 100 GHz are characterized. The first device is designed to support a comb of six modes and generates near Fourier limited 1.9 ps pulses. The second supports four primary modes resulting in a sinusoidal modulation of the optical intensity. Using a cross-correlation technique, we measured a 20 fs pulse to pulse timing jitter for the first device, while, for the second device, a mode-beating (RF) linewidth of 1 MHz was measured using heterodyne mixing in a semiconductor optical amplifier. Comparison of these results with those obtained for an equivalent Fabry-Perot laser indicates that the spectral filtering mechanism employed does not adversely affect the timing properties of these passively mode-locked devices.
Highlights
Optical data transmission and signal processing are driving increasing interest in the generation of optical carriers with specially tailored intensity modulation
Techniques involving modulation of a continuous wave single mode laser driven by an electronic synthesizer can provide optical carriers with narrow linewidth, but external optical filtering of a pair of modes is necessary to remove unwanted harmonics [6, 7]
Higher repetition rates have been achieved by harmonic mode-locking techniques including colliding pulse mode-locking [14,15,16] and in devices based on compound cavities [17, 18], but these approaches do not in general allow us to address modal intensities on an individual basis
Summary
Optical data transmission and signal processing are driving increasing interest in the generation of optical carriers with specially tailored intensity modulation. We have developed a simple intracavity spectral filtering technique that selects a finite number of modes in standard monolithic Fabry-Perot (FP) diode laser [19]. In these so-called discrete mode (DM) lasers, our design approach in principle allows us to fix the harmonic frequency and to tailor the intensity profile of the mode-locked laser output. We present measurements of timing jitter and mode-beating linewidth for two devices with mode-locking frequencies of 100 GHz. A natural benchmarking device for this study is a plain Fabry-Perot diode laser with the same cavity length.
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call