An optical comb source based on a slab-coupled optical waveguide amplifier (SCOWA) is presented. The laser is
harmonically mode-locked at 10.287 GHz repetition rate and stabilized to an intra-cavity Fabry-Pérot etalon via Pound-
Drever-Hall locking. The Fabry-Pérot etalon serves as a reference for the optical frequency of the comb-lines and
suppresses the fiber cavity modes to allow only a single longitudinal mode-set to oscillate, generating a frequency comb
spaced by the repetition rate. The pulse-to-pulse timing jitter and energy fluctuations are < 2 fs and < 0.03%,
respectively (integrated from 1Hz to 100 MHz). Fundamental to this result is the incorporation of the SCOW amplifier
as the gain medium and the use of an ultra-low noise sapphire-loaded cavity oscillator to mode-lock the laser. The
SCOWA has higher saturation power than commercially available gain media, permitting higher intra-cavity power as
well as available power at the output, increasing the power of the photodetected RF tones which increases their signal-to-noise
ratio. A high visibility optical frequency comb is observed spanning ~3 nm (at -10 dB), with optical SNR > 60 dB
for a cavity with no dispersion compensation. Initial results of a dispersion compensated cavity are presented. A spectral
width of ~7.6 nm (-10 dB) was obtained for this case and the pulses can be compressed to near the transform limit at
A CW injection locked Coupled Opto-Electronic Oscillator (COEO) is presented with a 10.24 GHz spaced optical frequency comb output as well as a low noise RF output. A modified Pound-Drever-Hall scheme is employed to ensure long-term stability of the injection lock, feeding back into the cavity length to compensate for cavity resonance drifts relative to the injection seed frequency. Error signal comparison to an actively mode-locked injection locked laser is presented. High optical signal-to-noise ratio of ~35 dB is demonstrated with >20 comblines of useable bandwidth. The optical linewidth, in agreement with injection locking theory, reduces to that of the injection seed frequency, <5 kHz. Low amplitude and absolute phase noise are presented from the optical output of the laser system. The integrated pulse-to-pulse energy fluctuation was found to be reduced by up to a factor of two due to optical injection. Additional decreases were shown for varying injection powers.
Fast and precise measurements of ultrafast optical waveforms are essential to the development of optical coherent
signal processing. In this paper, multi-heterodyne mixing of stabilized optical frequency combs is presented as a
simple technique for the measurement of ultrafast laser pulses and exotic arbitrary optical waveforms. This
technique takes advantage of both the broadband nature of the frequency comb and the narrow line-width of the
individual comb-lines to produce an array of radio-frequency beat-notes that share the characteristics of the optical
spectrum. Measurements of comb characteristics across THz of bandwidth are enabled by this method, while
maintaining the accuracy at the level of the individual comb-line width. Results show that both frequency
modulation and amplitude modulation combs can be measured using this scheme.
This work presents group delay measurements for a 1.3 μm quantum dot semiconductor optical amplifier at various
injection currents. White-light interferometry is used to obtain group delay data spanning both ground state and first
excited state transitions, ranging from 1200 nm to 1320 nm. The group delay, group velocity dispersion and existence of
higher order dispersion is observed and quantified.
We study the propagation properties of X-shaped localized higher-order Mathieu pulses. Several spectral functions
in the optical domain are proposed and discussed using physical examples. We derive the relevant expressions
using a formalism based on the angular spectrum of plane waves.
We obtain X-shaped localized pulses based on a superposition of non-diffracting optical fields of different frequencies.
We explore the construction of arbitrary traveling electromagnetic pulses that remain invariant in shape and re-derive an
expression for these pulses in terms of non-diffracting beams with arbitrary transverse distribution. We emphasize in the
known orthogonal families of solutions to the wave equation that have translation symmetries in only one dimension (i.e.
Bessel, Mathieu and Parabolic beams). We present several examples of higher order Mathieu localized pulses as well as
Parabolic pulses of arbitrary parabolicity. We consider feasible spectral functions in the optical domain.