Dispersion measurements of a 1.3 mu m quantum dot semiconductor optical amplifier over 120 nm of spectral bandwidth

Group delay and higher order dispersion measurements are conducted on a 1.3 mu m quantum dot semiconductor optical amplifier at various injection currents. White-light spectral interferometry is performed, along with a wavelet transform to recover the group delay. The group delay, group velocity dispersion, and higher order dispersion terms are quantified. The measurement spans both ground state and first excited state transitions, ranging from 1200 to 1320 nm. The group velocity dispersion, beta(2), is found to be -6.3x10(3) fs(2) (7.6 fs/nm) at an injection current of 500 mA

Intracavity Gain And Absorption Dynamics Of Hybrid Modelocked Semiconductor Lasers Using Multiple Quantum Well Saturable Absorbers

Time resolved intracavity gain, saturable absorption dynamics, intracavity intensity pulse profiles, and their corresponding spectrograms, were measured in an external cavity hybrid mode-locked semiconductor diode laser. These measurements were performed to obtain fundamental information of the mode-locking dynamics and to determine their role in the pulse shaping and chirping dynamics. The results of these experiments show that the integrating nonlinearity associated with gain depletion, coupled with group velocity dispersion, leads to asymmetric intensity pulse profiles with predominantly cubic temporal phase, while saturable absorption coupled with group velocity dispersion tends to linearize the chirp. Exploitation of these dynamics may allow researchers to generate optical pulses with higher peak intensities than previously reported

Measurement of carrier envelope offset frequency for a 10 GHz etalon-stabilized semiconductor optical frequency comb

We report Carrier Envelope Offset (CEO) frequency measurements of a 10 GHz harmonically mode-locked, Fabry-Perot etalon-stabilized, semiconductor optical frequency comb source. A modified multi-heterodyne mixing technique with a reference frequency comb was utilized for the measurement. Also, preliminary results from an attempt at f-2f self-referencing measurement are presented. The CEO frequency was found to be similar to 1.47 GHz for the particular etalon that was used

Supermode suppression to below-130 dBc/Hz in a 10 GHz harmonically mode-locked external sigma cavity semiconductor laser

We demonstrate supermode suppression to levels below - 125 dBc/Hz and - 132 dBc/Hz using Fabry-Perot etalons with finesse values of 180 and 650, respectively, for a 10 GHz harmonically mode-locked external sigma cavity semiconductor laser. The laser was hybridly mode-locked using direct electrical modulation in a compact package without the need for an external modulator

Dynamic line-by-line pulse shaping with GHz update rate

We introduce a novel scheme for dynamic line-by-line pulse shaping with GHz update rates. Four lines of an optical frequency comb source are used to injection-lock four individual VCSEL, which are subsequently electrically modulated at 0.4 to 1GHz through current modulation. This concept could be considered a completely new way of pulse shaping as the light is not simply modified, but rather regenerated with the desired properties. We also discuss an important drawback of line-by-line pulse shapers that ultimately limits the modulation speed capability

Comb-Based Radio-Frequency Photonic Filters with Rapid Tunability and High Selectivity

Photonic technologies have received considerable attention for enhancement of radio-frequency (RF) electrical systems, including high-frequency analog signal transmission, control of phased arrays, analog-to-digital conversion, and signal processing. Although the potential of radio-frequency photonics for implementation of tunable electrical filters over broad RF bandwidths has been much discussed, realization of programmable filters with highly selective filter lineshapes and rapid reconfigurability has faced significant challenges. A new approach for RF photonic filters based on frequency combs offers a potential route to simultaneous high stopband attenuation, fast tunability, and bandwidth reconfiguration. In one configuration tuning of the RF passband frequency is demonstrated with unprecedented (~40 ns) speed by controlling the optical delay between combs. In a second, fixed filter configuration, cascaded four-wave mixing simultaneously broadens and smoothes comb spectra, resulting in Gaussian RF filter lineshapes exhibiting extremely high (>60 dB) main lobe to sidelobe suppression ratio and (>70 dB) stopband attenuation.Comment: Updated the submission with the most recent version of the pape

Theoretical Study Of Spur-Free Dynamic Range Of A Semiconductor Resonant Cavity Linear Interferometric Intensity Modulator

Simulation results of the performance of a semiconductor resonant cavity linear interferometric intensity modulator are presented. Starting from the rate equations of an injection locked semiconductor laser, the phase response and stable locking range of the injection locked semiconductor laser were obtained. Within the stable locking range without any approximation on the injection power level, effects of the alpha parameter or linewidth enhancement factor of the injection locked semiconductor slave laser, injection ratio, refractive index, and the residual amplitude modulation on the spur-free dynamic range (SFDR) of the modulator are studied. © 2011 SPIE

Dual-Mode Injection Locking Of Two Independent Modelocked Semiconductor Lasers

A novel method of optical injection locking to obtain efficient synchronisation between independent sets of optical frequency combs from two modelocked semiconductor lasers is presented. Locking dynamics are experimentally observed and the performance of oscillator synchronisation is demonstrated by an optical heterodyne detection experiment

Towards Terabit Networking, Instrumentation And Signal Processing Using Hybrid Wdm-Otdm Technologies

We utilize a novel hybrid wavelength division multiplexed, optical time division multiplexed (WDM-OTDM) modelocked semiconductor laser for applications in ultrahigh data rate communication links, computer interconnects, and optical sampling applications. The key philosophy behind using a hybrid approach is that state-of-the-art system performance can be achieved without the necessity of operating at the limits of either a pure WDM or OTDM technology platform