Amplitude noise of subharmonically hybrid mode-locked pulses generated from a monolithic semiconductor laser (original) (raw)
Related papers
Noise of mode-locked lasers (Part II): timing jitter and other fluctuations
Applied Physics B, 2004
This work present a comprehensive discussion of the noise properties of mode-locked lasers, with an emphasis on the effect of quantum noise in passively mode-locked solid-state lasers. Of special interest is the timing jitter, which is coupled to noise in various other pulse parameters. The study is based on analytical results and on numerical tools as described in part one of this study. It results in useful guidelines for the comparison and optimization of different kinds of lasers concerning timing jitter.
2006
This dissertation explores various aspects and potential of optical pulse generation based on active, passive, and hybrid mode-locked quantum dot semiconductor lasers with target applications such as optical interconnect and high speed signal processing. Design guidelines are developed for the single mode operation with suppressed reflection from waveguide discontinuities. The device fabrication procedure is explained, followed by characteristics of FP laser, SOA, and monolithic two-section devices. Short pulse generation from an external cavity mode-locked QD two-section diode laser is studied. High quality, sub-picosecond (960 fs), high peak power (1.2 W) pulse trains are obtained. The sign and magnitude of pulse chirp were measured for the first time. The role of the self-phase modulation and the linewidth enhancement factor in QD mode-locked lasers is addressed. The noise performance of two-section mode-locked lasers and a SOA-based ring laser was investigated. Significant reduction of the timing jitter under hybrid mode-locked operation was achieved owing to more than one order of magnitude reduction of the linewidth in QD gain media. Ultralow phase noise performance (integrated timing jitter of a few fs at a 10 GHz repetition rate) was demonstrated from an actively mode-locked unidirectional ring laser. These results show that quantum dot mode-locked lasers are strong competitors to conventional semiconductor lasers in noise performance. Finally we demonstrated an opto-electronic oscillator (OEO) and coupled opto-electronic oscillators (COEO) which have the potential for both high purity microwave and low noise optical pulse generation. The phase noise of the COEO is measured by the photonic delay line iv frequency discriminator method. Based on this study we discuss the prospects of the COEO as a low noise optical pulse source. v ACKNOWLEDGMENTS I would like to express my deepest gratitude to Professor Peter J. Delfyett, Jr. for his great support, guidance, and inspiring discussion. His enthusiasm toward research motivated me all the time.
Optical phase noise and carrier-envelope offset noise of mode-locked lasers
Applied Physics B, 2006
The timing jitter, optical phase noise, and carrierenvelope offset (CEO) noise of passively mode-locked lasers are closely related. New key results concern analytical calculations of the quantum noise limits for optical phase noise and CEO noise. Earlier results for the optical phase noise of actively mode-locked lasers are generalized, particularly for application to passively mode-locked lasers. It is found, for example, that mode locking with slow absorbers can lead to optical linewidths far above the Schawlow-Townes limit. Furthermore, modelocked lasers can at the same time have nearly quantum-limited timing jitter and a strong optical excess phase noise. A feedback timing stabilization via cavity length control can, depending on the situation, reduce or greatly increase the optical phase noise, while not affecting the CEO noise. Besides presenting such findings, the paper also tries to clarify some basic aspects of phase noise in mode-locked lasers. PACS 42.50.Lc; 42.60.Fc with the CEO frequency ν ceo [3] and an integer index j. The CEO frequency is typically chosen to be between 0 and f rep , 266 Applied Physics B -Lasers and Optics
Journal of Lightwave Technology, 2000
Excess noise converted from the optical relative intensity noise (RIN) has limited the noise performance in the microwave signal synthesis application for mode-locked lasers. In this paper, a method for detailed characterization of the excess noise conversion from the optical RIN to the electrical pulse width jitter (PWJ), electrical relative amplitude noise (RAN) and electrical phase noise in the photodetection of mode-locked lasers is proposed. With the measured noise conversion ratios, one can predict the electrical RAN and phase noise power spectral densities under different input optical powers. The effect of the pulse width and peak power of the incident optical pulses and the effect of the saturation power of the photodetectors are also investigated. The results are used to suggest guidelines for achieving low-noise photodetection for microwave signal synthesis application.
Noise of mode-locked lasers (Part I): numerical model
Applied Physics B, 2004
A numerical model for the calculation of noise spectra of actively or passively mode-locked lasers has been developed. Fluctuations not only of the timing error, but also of all other quantities of interest can be quantified. The model is based on a pulse propagation algorithm with quantum noise sources. It allows the study of a much wider class of phenomena than those accessible with analytical techniques, and it is useful for testing the validity limits of analytical results. PACS 43.50.+y, 42.50.Lc, 42.60.Fc 2 Definitions for the characterization of noise
Characterization of the noise and correlations in harmonically mode-locked lasers
Journal of the Optical Society of America B, 2002
In a harmonically mode-locked laser multiple optical pulses propagate inside the laser cavity. The noise in different pulses inside the laser cavity is in general correlated. Information regarding the sign and magnitude of the noise correlations is contained in the distribution of the spectral weight among the supermode noise peaks that appear in the pulse energy and timing noise spectral densities. We show that the supermode noise spectrum obtained experimentally by measurement of the photodetector current noise spectral density can be used to determine the correlations in the energy and the timing noise of different pulses in the laser cavity. We also present simple models for the timing noise in harmonically mode-locked lasers that demonstrate the relationship between the noise correlations and the supermode noise peaks.
Timing jitter in passively mode-locked semiconductor lasers
arXiv: Optics, 2014
We study the effect of noise on the dynamics of passively mode-locked semiconductor lasers both experimentally and theoretically. A method combining analytical and numerical approaches for estimation of pulse timing jitter is proposed. We investigate how the presence of dynamical features such as wavelength bistability affects timing jitter.
Quantum Noise of Actively Mode-Locked Lasers With Dispersion and Amplitude/Phase Modulation
IEEE Journal of Quantum Electronics, 2004
A quantum theory for the noise of optical pulses in actively mode-locked lasers is presented. In the presence of phase modulation and/or group velocity dispersion, the linear operator that governs the time evolution of the pulse fluctuations inside the laser cavity is not Hermitian (or normal) and the eigenmodes of this operator are not orthogonal. As a result, the eigenmodes have excess noise and the noise in different eigenmodes is highly correlated. We construct quantum operators for the pulse photon number, phase, timing, and frequency fluctuations. The nonorthogonality of the eigenmodes results in excess noise in the pulse photon number, phase, timing, and frequency. The excess noise depends on the frequency chirp of the pulse and is present only at low frequencies in the spectral densities of the pulse noise operators.