Optimised design of fibre-based pulse compressor for gain-switched DFB laser pulses at 1.5 [micro sign]m

Barry, Liam P.; Thomsen, Benn C.; Dudley, John M.; Harvey, J.D.

doi:10.1049/el:19990782

Cited by 9 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The (linewidth × time) products (FWHM) of the pulses generated had values between 0.32 and 0.44. Since then, DFB gain-switched lasers have become a popular means of generating single-frequency low-chirp pulses of 25 to 30 ps duration [133][134][135].…”

Section: Optical Spectra Of Gain-switched Pulsesmentioning

confidence: 99%

Fast phenomena in semiconductor lasers

2000

View full text Add to dashboard Cite

Although diode lasers are almost ideal sources for ultrahigh-speed data communication systems, system performance remains critically dependent on the quality of the optical pulses that they generate. Uniquely among lasers, the output power can be modulated directly by modulating the diode current. However, this leads to relaxation oscillations and a roll-off at high frequencies that is superimposed on the frequency response of the drive circuit. This is limited by parasitics and maximum modulation frequencies range from 1 to 70 GHz, depending on the type of laser and its packaging. The higher values are obtained with short cavity lengths and tight optical confinement, the highest frequencies being achieved in vertical-cavity devices. Modulation bandwidth is usually limited by circuit parasitics, device heating and the maximum power-handling capability of the laser facets.The generation of picosecond and femtosecond pulses demands special techniques and three-gain switching, Q-switching and mode locking-are discussed in detail, with their relative advantages and disadvantages compared. Very short pulses inherently contain a significant spread of wavelengths and their generation requires the optical gain in the laser medium to extend across that wavelength range. While diode lasers satisfy this criterion better than many other types, the effect of gain non-linearities and carrier-transport effects prevent the Fourier-transform limit from being achieved in practice. As a result, external pulse-compression techniques, which exploit the detailed temporal and spectral properties of the laser pulses, such as frequency chirping, self-phase modulation and group velocity dispersion, are becoming more important, and diode lasers are increasingly challenged as primary sources by compact, efficient, diode-pumped solid-state lasers.The paper summarizes the levels of maximum pulse power and minimum duration that have been achieved using the various techniques.

show abstract

Section: Optical Spectra Of Gain-switched Pulsesmentioning

confidence: 99%

Fast phenomena in semiconductor lasers

2000

View full text Add to dashboard Cite

show abstract

“…However, it is clearly advantageous to be able to optimize the pulses generated at the transmitter before employing them in the overall system. In addition, if the complete intensity and phase of the data signal at the transmitter is known, then the system designers will be able to accurately model the transmission of these data signals through the fiber networks [8] and also determine the exact level of dispersion compensation and management that the system will require. In this letter, we have shown that by using the FROG measurement technique, we can retrieve the complete intensity and phase of optical pulses generated using a CW laser diode followed by an external modulator.…”

Section: Discussionmentioning

confidence: 99%

Optimization of optical data transmitters for 40-Gb/s lightwave systems using frequency resolved optical gating

Barry

Burgo²,

Thomsen

et al. 2002

IEEE Photon. Technol. Lett.

Self Cite

View full text Add to dashboard Cite

Abstract-The measurement technique of frequency resolved optical gating has been used to optimize the phase of a 40-GHz train of optical pulses generated using a continuous-wave laser gated with an external modulator. This technique will be vital for optimization of optical transmitters to be used in systems operating at 40 Gb/s and beyond, as standard measurement techniques will not suffice to optimize such high-speed systems.

show abstract

“…5 To predict optical pulse profiles properly in time and frequency domains at each pulse compression stage, it is essential to know the parameters of the gain-switched pulse, such as pulse shape, pulse width, and, most of all, the frequency chirp information of the pulse for optimum pulse compression. 6 The gain-switched pulse is broadly regarded as having linear frequency chirp only, but the actual gain-switched pulse has almost linear chirp around the center of the optical pulse and nonlinear frequency chirp in the vicinity of leading or trailing edges. The presence of nonlinear frequency chirp cannot be overcome due to the variations of carrier density in the gain medium during the pulse buildup time.…”

Section: Introductionmentioning

confidence: 99%

Complete chirp analysis of a gain-switched pulse using an interferometric two-photon absorption autocorrelation

et al. 2006

View full text Add to dashboard Cite

We propose a simple but powerful scheme for the complete analysis of the frequency chirp of a gainswitched optical pulse using a fringe-resolved interferometric two-photon absorption autocorrelator. A frequency chirp imposed on the gain-switched pulse from a laser diode was retrieved from both the intensity autocorrelation trace and the envelope of the second-harmonic interference fringe pattern. To verify the accuracy of the proposed phase retrieval method, we have performed an optical pulse compression experiment by using dispersion-compensating fibers with different lengths. We have obtained close agreement by less than a 1% error between the compressed pulse widths and numerically calculated pulse widths.

show abstract

Optimised design of fibre-based pulse compressor for gain-switched DFB laser pulses at 1.5 [micro sign]m

Cited by 9 publications

References 7 publications

Fast phenomena in semiconductor lasers

Fast phenomena in semiconductor lasers

Optimization of optical data transmitters for 40-Gb/s lightwave systems using frequency resolved optical gating

Complete chirp analysis of a gain-switched pulse using an interferometric two-photon absorption autocorrelation

Contact Info

Product

Resources

About