Widely tunable high-power diode lasers

Tunable diode laser sources in the near infrared are needed for several applications, such as absorption spectroscopy, bio-medical imaging and frequency conversion, e.g., up-conversion and terahertz frequency generation. Common for these applications is the need for high-power, diffraction-limited, and tunable narrow linewidth laser sources. Corresponding light sources developed in the Laser Sensors Lab are based on hybrid master oscillator power amplifiers.

  • Hybrid Y-branch dual-wavelength MOPA system
    [+] Hybrid Y-branch dual-wavelength MOPA system
  • Schematic drawing of Y-branch dual-wavelength MOPA system
    [+] Schematic drawing of Y-branch dual-wavelength MOPA system
  • Hybrid sampled grating MOPA system
    [+] Hybrid sampled grating MOPA system
  • Schematic drawing of a hybrid sampled grating MOPA system
    [+] Schematic drawing of a hybrid sampled grating MOPA system

Working principle

Laser emission of a wavelength tunable diode laser as master oscillator is coupled into a power amplifier. This enables increased optical output powers while the spectral and spatial characteristics of the master oscillator are maintained. Using Y-branch DBR diode lasers with electrically controlled micro-heaters, implemented above the gratings provide dual-wavelength laser emission and wavelength tuning over several nanometers. With sampled grating lasers, recently developed at FBH using GaAs based devices for the first time, wider wavelength tuning of several tens of nanometers is obtained.

Current applications

  • Nonlinear up-conversion of infrared emission

Typical wavelengths

  • 976 nm (9.7 nm tuning range)

Technology and mounting

  • Diode lasers with vertical layer structures realized by MOVPE
  • Anti-reflection coating of laser facets
  • Active assembly of optical components on micro-optical bench
  • Characterization of electro-optical, spectral and special properties

The Mid-TECH ITN project has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 642661 (duration 01.01.2015 – 31.12.2018).