Research Topics of Lasers Group

Laser diodes are being developed for a variety of applications in the area of optical tele- and data communications, and sensors. This development work mainly aims at improving laser performance as well as reducing costs related to processing, testing, and eventually packaging. Depending on the specific device the wavelength range between about 1200 nm and 1900 nm is covered. Bulk-InGaAsP-, QW-InGaAsP-, QW-InGaAlAs-, combinations thereof, and most recently also quantum dot (QD) structures are used as active layer.

Our current research, development, design and fabrication activities cover the following topics:

  • Fabry-Perot and DFB laser diodes with tapered output for high coupling efficiency
  • lasers for 10 Gb/s uncooled direct modulation
  • EMLs for 25…40 Gb/s direct modulation
  • Tapered curved stripe design DFB lasers (CSDFB) with better single mode yield and less influence of external reflactions
  • surface emitting DFB lasers (HCSEL, horizontal cavity design)
  • DFB lasers for sensing applications and other industrial applications
  • medium power DFB lasers up to 150 mW
  • high power FP laser diodes up to 700 mW single spatial mode and 3 W broad area
  • optical amplifiers and gain elements for external cavity lasers
  • multi-section lasers (s. right column)
  • 40 Gbit/s passive feedback lasers
  • 1450-1550 nm High Power Laser Diodes with 18W pulsed- and 4W CW-output power

All devices are completely fabricated at HHI using our InP processing line. Characterisation and chip selection is carried out using an automatic bar measurement system, including the capability of 40Gbit/s characterization on bar level. Mounted devices can be fully characterised with respect to all relevant laser parameters such as output power, optical farfield, modal gain, relative intensity noise (RIN), frequency response.

Top view of Curved Stripe DFB (CSDFB) - Laser
Front facet of Horizontal Cavity Surface Emitting Laser (HCSEL)
Mounted HCSEL-Laser
40 Gbit/s Directly Modulated Laser
EML device and corresponding eye diagram