Vertical-cavity surface-emitting lasers with liquid crystal overlay

Project Details


Context Liquid crystals are materials that are widely used in displays nowadays, but they are becoming more and more popular for applications in photonics. They have unique electro-optic and opto-optic properties. This means that the optical behavior can be altered by applying either an electrical or an optical signal. The main advantage is that a large optical effect (in terms of refractive index change) can be obtained with very modest electrical or optical fields. Spatial soliton generation for example has been demonstrated in liquid crystal devices with only a few mW of light power and only a few volts of bias voltage, while this is impossible with other material systems that require either large optical power ors large bias voltages. VCSELs are a new class of semiconductor lasers that contrary to conventional edge emitting semiconductor lasers that emit light perpendicular to the top surface. This gives the possibility to epitaxially grow monolithic multilayer devices with wavelength size cavity length in order to prevent multi-longitudinal mode operation and high reflectivity Distributed Bragg Mirrors (DBRs) to decrease the threshold current. Another advantage is that 2-dimensional arrays of VCSELs can be implemented on a single chip. However, due to their new cavity design VCSELs face new problems, such as multi-transverse mode emission for increased size of the laser aperture and unstable polarization behavior, polarization mode hopping and switching. The main goal of this project is to combine VCSELs with a liquid crystal overlay in order to solve abovementioned issues and to add new functionalities such as, for example, tuning the emission wavelength and modal properties of the VCSEL. On the other hand, the VCSEL can be used as a light source to directly induce nonlinear effects in the liquid crystal layer, instead of using external light sources. New interesting features become possible when both technologies are integrated
Effective start/end date1/01/0931/12/12

Flemish discipline codes

  • Physical sciences
  • Mathematical sciences
  • Electrical and electronic engineering


  • Holography
  • Non-Linear Optics
  • Photonics
  • Optival Instrumentation
  • Optical Computing
  • Semiconductor Technology
  • Optical Fibre Sensors
  • Optical Switches And Modulators
  • Optical Measurements
  • Optical Interconnects
  • Optical Materials
  • Vcsels
  • Optical Instrumentation
  • Micro-Optics
  • Opto-Electronic Devices
  • Plastic Photonics