Wide-wavelength-tunable distributed Bragg reflector laser diode with high thermal efficiency

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Photonics

Background:

• Distributed Bragg reflector (DBR) laser diodes are crucial for tunable light sources.
• Thermal tuning offers a method for wavelength adjustment in DBR laser diodes.
• Existing thermal tuning methods face limitations in tuning efficiency and range.

Purpose of the Study:

• To propose and demonstrate a thermally-tuned DBR laser diode with enhanced tuning efficiency.
• To achieve a wide wavelength tuning range using a novel thermal isolation structure.
• To develop a cost-effective fabrication process for improved DBR laser diodes.

Main Methods:

• Fabrication of a DBR laser diode incorporating a gain, phase control (PC), and DBR region.
• Implementation of micro-heaters on the DBR and PC regions for coarse and fine tuning.
• Development of a thermal isolation structure using a reverse mesa etching process, avoiding InGaAs sacrificial layers.

Main Results:

• The fabricated DBR laser diodes exhibit effective heat confinement due to the thermal isolation structure.
• An approximate wavelength tuning range of 40 nm was achieved.
• This represents a nearly four-fold increase in tuning range compared to devices without thermal isolation.

Conclusions:

• The novel thermal isolation technique significantly enhances the wavelength tuning range of DBR laser diodes.
• This approach offers a cost-effective solution for developing wide-wavelength-tuning DBR laser diode light sources.
• The technology is suitable for applications requiring tunable laser sources with a broad spectral coverage.