Effects of annealing on performances of 1.3-μm InAs-InGaAs-GaAs quantum dot electroabsorption modulators

Abstract

In this work, we investigated the effects of quantum dot (QD) annealing (as-grown, 600°C-annealed, and 750°C-annealed) on the preliminary performances of 1.3-μm InAs-InGaAs-GaAs quantum dot electroabsorption modulators (QD-EAMs). Both extinction ratio and insertion loss were found to vary inversely with the annealing temperature. Most importantly, the 3-dB response of the 750°C-annealed lumped-element QD-EAM was found to be 1.6 GHz at zero reverse bias voltage - the lowest reverse bias voltage reported. We believe that this work will be beneficial to researchers working on on-chip integration of QD-EAMs with other devices since energy consumption will be an important consideration.

Monolithically Integrated Quantum Dot Electro-Optic Modulator with Semiconductor Optical Amplifier for Short-Reach Optical Communications

“…Techniques such as electro-absorption (EA) modulation are employed to achieve compact devices and high-data-rate optical signal generation. Optical data generation at up to 2.5-Gb/s by an external modulator using the EA effect of QDs was previously reported [5]. We expect that complicated short-reach networks will become smart by using the broadband optical frequency resource of the QD optical gain in the T+O band.…”

Electro-absorption and Electro-optic Characterization of L-Band InAs/InP Quantum-dash Waveguide

“…It is worth mentioning here that double the cavity length was used here for L in order to account for the round trip of the injected and reflected beam. As such, n was solved for in (2) under each applied reverse bias voltage, and thereafter n was calculated with reference to the 0 V bias case. The obtained n value is shown in Fig.…”

“…Consequently, most attention and effort in this field has been focused in employing these novel structures as optical sources, particularly mode-locked lasers, and optical amplifiers in optical fiber telecommunication systems [1]. Nevertheless, a very limited amount of work has been carried out in employing QDot-based structures as external modulators in the form of electro-absorption (EA) modulators (EAM) or electro-optic (EO) modulators (EOM) [2], which have been employed extensively in quantum-well (QWell) structures [3][4][5][6].…”

“…Conversely, low ERs of 2.1 and 3.5 dB were reported on InAs and InGaAs QDot structures, respectively, in [7] and [8], emitting around 1300 nm even when biased at high reverse bias voltage of −10 V in the former case. Recently, an improved performance from an InAs (InGaAs) QDot waveguide was reported in [2] ( [9]) exhibiting an ER of 10 dB (10.5 dB) at 1300 nm when biased at −8 V. Moreover, in order to improve the device characteristics, a thin GaP tensile strain compensation layer between the different QDot layers was incorporated [10], with the demonstration of the best ER of 13 dB at -8 V, to the authors' knowledge, over the QDot platform. However, this was only possible to be achieved at the cost of ten QDot layers.…”

Monolithically integrated quantum dot optical modulator with Semiconductor optical amplifier for short-range optical communications

“…Recently, an EA effect and development of a compact EA modulator using the QD structure was thoroughly investigated, and an optical data generation of up to 2.5 Gbps with the external QD EA modulator was reported. 28,29) We anticipate that complicated short-reach network systems will be streamlined by using the broadband optical frequency resource provided by the QD optical gain in the T+O band. Therefore, we focused on developing a QD optical gain modulator (OGM) device using the broadband optical gain change.…”