160 GHz harmonic mode-locked AlGaInAs 155μm strained quantum-well compound-cavity laser

Abstract

We characterized the reflectivity and the modal discrimination of intracavity reflectors (ICRs) with different numbers of slots and presented harmonic mode-locking operation of a monolithic semiconductor laser comprising a compound cavity formed by a single deeply etched slot ICR fabricated from 1.55 μm AlGaInAs strained quantum well material. Gaussian pulses were generated at a 161.8 GHz repetition rate with a pulse duration of 1.67 ps and a time-bandwidth product of 0.81.

Mode-Locked Laser Diodes and Their Monolithic Integration

“…7 shows the measured autocorrelation traces and their corresponding optical spectra for single-and 2-slot ICR lasers. It is apparent that, at the harmonic number M = 4, the laser with a single-slot ICR produced the best ML operation which again is in good agreement with the simulated results in [12], [42]. Pure HML of the device at harmonic number of M = 4 was observed by forward biasing the two gain sections (60 mA ≤ I GS 1 ≤ 80 mA, 0 mA ≤ I GS 2 ≤ 20 mA) and reverse biasing the absorber section (|V S A | ≥ 2.0 V).…”

“…The theoretical analysis performed in [11] implied that, while the accurate positioning of intra-cavity reflectors (ICRs) in the cavity was important for CCM operation, the stability of the CCM regime could be potentially higher than that of the rival CPM approach due to the strong linear modal selectivity of the compound cavity. We have used the CCM approach to transfer the idea presented in [11] to the telecoms-relevant wavelength of 1.5 μm [42] in which we focused primarily on the device performance of ridge waveguide lasers with a single-and 2-slot ICR.…”

AlGaInAs mode-locked lasers for ultrashort pulse harmonic mode locking

“…The samples used in the experiment were based on commercial AlInGaAs 1550 nm laser diode (LD) wafers [5] [6]. Active region consisted of 5 6-nm-thick quantum wells separated by 10-nm-thick barriers, where both wells and barriers are of Al-quaternary material.…”

“…A promising way of achieving high frequency repetition rates is to introduce harmonic ML techniques. A harmonic MLL produces an optical pulse train at a harmonic of the fundamental round-trip frequency of the device, which can be achieved by methods including subharmonic optical injection [3], colliding pulse ML (CPM), including multiple and asymmetric (see references in [1]), and compound-cavity ML (CCM) [4]- [6]. We have followed the latter approach to transfer the idea presented in [4] to the communications-relevant wavelength of 1.5 μm.…”

160-GHz 1.55-$\mu{\rm m}$ Colliding-Pulse Mode-Locked AlGaInAs/InP Laser With High Power and Low Divergence Angle

“…Higher pulserepetition rates can be achieved with a longer cavity using harmonic mode-locking (ML) techniques, and one way to realize this is to use the colliding-pulse ML (CPM) configuration [3][4][5]. The monolithic CPM laser is a compact light source which is thermally and mechanically very stable, can be made with relatively simple fabrication processes and has less stringent cleaving tolerances compared with its compoundcavity counterpart [6]. The QW based 160 GHz 1.55 μm CPM laser demonstrated in [5] had quite a low average output power (10 mW).…”