Optimization of direct modulation rate for circular microlasers by adjusting mode Q factor

Abstract

Semiconductor microcircular lasers have been investigated as potential light sources for photonic integrated circuits and optical interconnections for more than two decades. However, the direct modulation bandwidths of the circular microlasers remain a challenge, especially when being compared with other microlasers, such as photonic crystal lasers. In this paper, microcircular lasers connected to an output waveguide are investigated for high-speed direct modulation with optimized mode Q factors. Small signal modulation with a resonance frequency of f R = 12.5 GHz is realized for a AlGaInAs/InP circular microlaser with a radius of 10 μm at 290 K. Furthermore, clear eye diagrams are observed at 12.5 Gbit/s for a 15-μm radius circular microlaser with f R = 6.9 GHz.

Mode Characteristics and Optical Bistability for AlGaInAs/InP Microring Lasers

“…The microring lasers were fabricated using an AlGaInAs/InP laser wafer with six compressively strained quantum wells as in [15]. (ICP) etching process and the top-view optical microscope image of a microring laser.…”

Integrated semiconductor twin-microdisk laser under mutually optical injection

“…4(b), the measured results at I b ¼ 19.0 and 19.2 mA could be fitted based on the small-signal response function. 14 The results indicate that laser A at injection locking state has enhanced 3-dB bandwidth of 16. Fig.…”

“…At the bias current I a ¼ 29 mA, the output light is amplified by 20 dB using an erbium-doped fiber amplifier (EDFA) and then passed through an optical filter to select the dominant lasing mode at 1550.08 nm before detected by a high-speed photodetector. 14 The small signal modulation response at 287 K is plotted in Fig. 1(d) By applying CW currents to the two microdisk lasers at the same time, we can investigate the nonlinear dynamics resulting from the mutually internal optical injection through the connected optical waveguide.…”

“…10 Due to the merits of small footprint and low power consumption, whispering-gallery mode (WGM) microcavity lasers have been investigated for applications in optical frequency conversion, signal processing, and optical interconnects. [11][12][13][14][15] The influence of optical injection on modulation characteristics has been investigated for a microring laser under the four-wave mixing (FWM) state. 16 Furthermore, different dynamical states including FWM, period-one and period-two oscillations, injection locking, and chaotic state have been realized for semiconductor microdisk lasers subject to external optical injection.…”

“…14 The microdisk resonators are laterally confined by a 200-nm SiN x layer and the benzocyclobutene (BCB) layer. The twin-microdisk lasers have the same radius of 10 lm and ring-pattern contact window with a ring width of 5 lm.…”