## Abstract

We present theoretically an AM mode-locked laser that can generate various kinds of optical pulses. By employing a non-perturbative master equation in the frequency domain, we show that we can design an arbitrary output pulse waveform, a(t) , output from a laser with a specific optical filter, F {A}(\omega) , characterized by a Fourier transformed spectral profile A(\omega) of a(t) , A(\omega +\Omega {m}) , and A(\omega -\Omega {m}). Here, \Omega {m} is the AM modulation frequency. Although the optical filter F{A}(\omega) generally has a complex frequency response, most F{A}(\omega) filters are characterized by real values as long as the mode-locked pulse waveform is symmetric in the time domain. However, F{A}(\omega) becomes spectrally complex when our aim is to generate an asymmetrically mode-locked waveform, for example a single-sided exponential pulse. The actual F{A}(\omega) can be designed by using, for example, a liquid crystal on silicon (LCoS) optical filter, which can simultaneously control the amplitude and the phase of the input signal. A sech pulse (soliton) has already been generated based on the nonlinear Schrödinger equation by using Kerr nonlinearity in a fiber, but we show in this paper that the pulse can be generated very precisely even without nonlinearity. Since the present method enables us to generate triangular, double-sided exponential pulses as well as Gaussian, sech, parabolic, and even Nyquist pulses in the amplitude expression, we may be able to use AM mode-locked lasers as optical function generators.

Original language | English |
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Journal | IEEE Journal of Quantum Electronics |

Volume | 57 |

Issue number | 6 |

DOIs | |

Publication status | Published - 2021 Dec 1 |

## Keywords

- Fourier analysis
- Mode-Locked laser
- optical filters
- optical function generator
- optical pulses

## ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering