Proposal of novel structure for wide wavelength tuning in distributed Bragg reflector laser diode with single grating mirror

• Published in: Optics express 2018-10, Vol.26 (22), p.28704-28712
• Main Authors: Kwon, Oh-Kee, Lee, Chul-Wook, Kim, Ki-Soo, Oh, Su-Hwan, Leem, Young-Ahn
• Format: Article
• Language: English
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.26.028704

We report a novel structure that is capable of wide wavelength tuning in the distributed Bragg reflector laser diode (DBR-LD) with a single grating mirror. This device's DBR section has two tuning elements, plasma, and heater tunings, which are implemented simultaneously on the top of a single waveguide by using an in-between dielectric layer. For the proposed structure, a three-dimensional thermal simulation was conducted. The results showed that the temperature profile within the waveguide is highly affected by the position of heater metal and thermal conductivity of the p-cladding layer. As a result, it is important to use a uniform temperature region in the DBR section for a wide tuning range and stable single-mode operation. For a 550-μm long DBR-LD with a 250-μm long DBR section, a tuning range of 26 nm (i.e., 7 nm for plasma tuning and 19 nm for heater tuning); an SMSR of more than 45 dB; and a peak power variation of less than ± 2.5 dB were obtained. From the comparisons of two DBR-LDs with only one tuning element, we confirmed that using the dielectric layer is a very effective way of achieving a wide tuning under the independent tuning operation.