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High-Power Tapered Distributed Bragg Reflector Laser Diodes Emitting at 1550 nm

Research output: Other conference contributionPaper, poster or abstractScientific


Original languageEnglish
Publication statusPublished - 18 May 2016
EventOptics and Photonics days - Hotel Torni , Tampere, Finland
Duration: 16 May 201618 May 2016


ConferenceOptics and Photonics days
Abbreviated titleOPD
Internet address


Compact LIDAR systems work in the near infrared (NIR) area, more specifically at wavelengths around 800 nm to 900 nm. In adverse weather the measurement range decreases dramatically as the light is attenuated by rain drops or fog. The penetration length can be improved by increasing the optical peak power of the lasers, but in the NIR spectral range the maximum emission power permitted due to eye safety is very limited and almost reached by the current systems. A significantly higher optical power can be used in the short wave infrared (SWIR) range. LIDAR systems working, for ex-ample, at 1550 nm are employed in military applications. However, these LIDAR systems are very bulky. This paper presents a compact high-power single-mode 1.55 µm laser diode for LIDAR applications.

The AlGaInAs/InP distributed Bragg reflector (DBR) lasers comprise a passive DBR section, an active ridge waveguide (RWG) section and tapered gain-guided sections of different lengths and have been fabricated without regrowth. Measurements indicate that the output power scales with the length of the tapered section and hint that one of the limiting factors for power scaling with the tapered section length is the non-uniform heating of the chip. According to thermal simulations, the non-uniform heating seems to cause devices with a long tapered section to roll-over at a much lower average power density than devices with a shorter tapered section.

Typical devices emit up to 560 mW in single-mode continuous wave operation at room temperature with a high spectral purity (38 dB side-mode suppression ratio, SMSR, at maximum power). By changing the length of the tapered section from 0.5 mm to 4.0 mm the maximum power could be increased from 125 mW to 560 mW. The tapered section and the RWG section are driven with separate currents. The maximum power was achieved with 10 A current to the tapered section and 350 mA current to the RWG section. The peak emission wavelength can be tuned by more than 2 nm either by changing the tapered section current (at a rate of about 0.4 nm/A) or by changing the temperature (at a rate of about 0.1 nm/ºC, between 10 ºC to 40 ºC).

Field of science, Statistics Finland