We study high-power high bit rate single-mode 1550 nm vertical-cavity surface-emitting lasers fabricated using wafer-fusion. The optical cavity was grown on an InP wafer, and the two AlGaAs/GaAs distributed Bragg reflectors were grown on GaAs wafers, all three by molecular-beam epitaxy. The active region is based on thin InGaAs/InAlGaAs quantum wells and a composite InAlGaAs tunnel junction. To confine current and optical radiation, we use a lateral-structured buried tunnel junction with ≈ 6 µm diameter and an etching depth of ≈ 20 nm. These VCSELs demonstrate up to 5 mW single-mode continuous-wave output power and a threshold current of ≈ 2 mA at 25 °C. Even at an ambient temperature of 85 °C, the maximum optical output power is larger than 1 mW. The lasers demonstrate a 34 Gbps non-return-to-zero data transfer rate and 42 Gbps (21 GBaud) using 4-level pulse amplitude modulation at 25 °C back-to-back conditions with ≈ 934 fJ/bit power consumption per bit, which is amongst the lowest values reported for this wavelength range and bit rate.
The paper presents the results of the research and development of 1300-nm vertical-cavity surface-emitting lasers, fabricated by wafer fusion technique for hybrid integration of an InAlGaAs/InP optical cavity with two AlGaAs/GaAs distributed Bragg reflectors using molecular-beam epitaxy. The active region is based on InGaAs/InAlGaAs superlattice, while current and optical confinement is provided by n++-InGaAs/p++-InGaAs/p++-InAlGaAs buried tunnel junction (BTJ). The proposed device design results in low internal loss (about 3.2 cm-1 at 20 °C). The devices with BTJ diameter of 5 μm demonstrate a stable single-mode lasing with threshold current less than 1.3 mA and output optical power more than 6 mW and operation in a wide temperature range. The measured -3 dB bandwidth is more than 8 GHz at 20 °C and about 5.5 GHz at 85 °C, the eye diagrams are open with a bit rate up to 20 Gbps using nonreturn-to-zero (NRZ) modulation standard. Using 5-tap feedforward equalizer, the NRZ transmission at 25 Gbps has been demonstrated up to 5km single-mode fiber.
We report for the first time on wafer-fused InGaAs-InP/AlGaAs-GaAs 1550 nm vertical-cavity surface-emitting lasers (VCSELs) incorporating a InAlGaAs/InP MQW active region with re-grown tunnel junction sandwiched between top and bottom undoped AlGaAs/GaAs distributed Bragg reflectors (DBRs) all grown by molecular beam epitaxy. InP-based active region includes seven compressively strained quantum wells (2.8 nm) optimized to provide high differential gain. Devices with this active region demonstrate lasing threshold current < 2.5 mA and output optical power > 2 mW in the temperature range of 10-70°C. The wall-plug efficiency (WPE) value-reaches 20 %. Lasing spectra show single mode CW operation with a longitudinal side mode suppression ratio (SMSR) up to 45 dB at > 2 mW output power. Small signal modulation response measurements show a 3-dB modulation bandwidth of ~ 9 GHz at pump current of 10 mA and a D-factor value of 3 GHz/(mA)1/2. Open-eye diagram at 30 Gb/s of standard NRZ is demonstrated. Achieved CW and modulation performance is quite sufficient for fiber to the home (FTTH) applications where very large volumes of low-cost lasers are required.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.