Characteristics of Wavelength Tunable Vertical-Cavity Surface-Emitting Laser Using Mesa Heater for Detecting Application

We fabricated mesa heater wavelength tunable vertical-cavity surface-emitting lasers (VCSELs) and observed the dependence of their wavelength tuning characteristics on the tuning current and measurement time. The mesa heater tunable VCSEL shows an emission wavelength of 787.5 nm and a line-width as narrow as 0.2 nm without any tuning current. A total tuning range of 5.3 nm was observed in polarized single mode operation mode over the whole tuning range. The tuning efficiency was 0.059 nm/mA and the side mode suppression ratio was larger than 30 dB over the whole tuning range. The concept of tunable VCSELs is suitable for the detecting system as compact label-free biosensor.