DFB pro

Distributed-feedback laser

  • Single-frequency laser with distributed-feedback diode
  • Available wavelengths: 633 nm, 760 nm .. 3500 nm
  • Mode-hop free tuning range: Up to 1400 GHz
  • Reliable operation even in harsh environments
  • 3 laser heads – wide range of options

Distributed feedback (DFB) lasers unite wide tunability and high output power. The frequency-selective element – a Bragg grating – is integrated into the active section of the semiconductor and ensures continuous single-frequency operation. Due to the absence of alignment-sensitive components, DFB lasers exhibit an exceptional stability and reliability. The lasers work under the most adverse environmental conditions – even in the Arctic or in airborne experiments.

Three laser heads, designed specifically for DFB lasers, accommodate different diode packages: the compact DFB pro and its “big brother” DFB pro L integrate 9 mm or TO3-type diodes. The DFB pro BFY offers a dedicated laser head for butterfly-type diodes.

Owing to their wide continuous tuning range, DFB lasers lend themselves particularly to applications in atomic and molecular physics, gas sensing, phase-shifting interferometry, and continuous-wave terahertz generation.

For a selection of available DFB/DBR laser diodes, please refer to the online stock list. If you are interested in a wavelength not shown there, please inquire – TOPTICA can provide customized DFB systems at virtually any wavelength between 760 nm and 3500 nm.

  • DFB pro
  • DFB pro
  • Specification
      DFB pro DFB pro L DFB pro BFY
    Center wavelengths 633 nm, 760 nm - 3500 nm 1064 nm .. 2000 nm *
    Output power 2 .. 150 mW  10 .. 100 mW (fiber output)
    Tuning range 2 .. 6 nm  2 .. 5 nm, mode-hop free
    Thermal tuning
       Typical range > 1000 GHz  > 600 GHz
       Typical speed 50 GHz / sec  25 GHz / sec
       Typical rate -25 GHz / K  -10 .. -15 GHz / K
    Electric tuning   
       Typical range 50 GHz  > 25 GHz
       Typical speed Up to MHz frequencies  Up to MHz frequencies
       Typical rate 1 .. 10 GHz / mA (@ 1 Hz speed)  0.3 .. 1.0 GHz / mA (@ 1 Hz speed)
    Typical linewidth (time scale 5 µs) 1 .. 4 MHz  0.5 .. 5 MHz
    Output beam characteristics Collimated, Ø 3 mm x 1 mm (1/e²; note: circular profile with Beam shaping / pro) Circular, divergent, Fiber NA typ. 0.12
    Output beam polarization Linear, > 100:1  Linear, typ. 100:1
    Fast modulation
    (AC and DC coupled)
    Included Included Included
    Beam shaping / pro Optional Optional --
    Optical isolators Optional, 30 dB ** Optional, 30 dB or 60 dB Included ***
    Fiber coupling SmartDock, optional FiberDock, optional Fiber pigtail
    Fiber coupling efficiency: min. (typ.) 50% (60%) 50% (60%) N.A.
    Fiber coupling efficiency with
    beam shaping / pro
    55% (65%) 55% (65%) N.A.
    Dimensions laser head (H x W x D) 45 x 90 x 165 mm**** 90 x 90 x 240 mm**** 55 x 130 x 165 mm
    Weight laser head 2 kg 3 kg 1 kg
    Typical wavelengths 633 nm 780 / 795 nm 1178 nm (butterfly)
      780 / 795 nm 852 / 895 nm 1.5 µm
      852 / 895 nm 1000-1100 nm 1.65 µm
      > 2 µm (free-beam, w/o isolator) 1178 nm 2 µm (butterfly)
    Dimensions control unit (H x W x D) 154 mm x 450 mm x 348 mm 
    Weight control unit 9 kg 
    Operating voltage 100 .. 240 V~, 50/60 Hz (wide-range input)
    Power consumption Typ. < 50 W, max. 250 W  
    PC Interface Ethernet
    Environmental temperature 15 - 30 °C (operating), 0 - 40 °C (storage and transport)
    Environmental humidity Non condensing

    * Spectral coverage with gaps
    ** Requires Beam shaping / pro
    *** Additional fiber isolators can be added upon request
    **** Without fiber coupler

  • Additional Information
  • Options

    Fiber Coupling (FiberDock)

    TOPTICA’s patented fiber coupler provides highest single-mode fiber-coupling efficiencies, easy alignment and at the same time highest stability. TOPTICA additionally offers a wide range of single-mode and polarization-maintaining fibers, including fiber-optic beam splitters. Optical isolation is mandatory for fiber-coupled diode laser systems.

    Optical Isolation

    Isolators are used to protect the laser diode against back reflections. This not only prevents damage to the diode but also ensures untroubled tuning and single-frequency operation. Fiber-coupling with angle-polished fibers (both ends) requires at least a single-stage isolator (> 30 dB). Double-stage isolators are needed if reflections from the experiment into the laser are expected. Fiber-coupling with non-angle-polished fibers also requires a double-stage isolator (> 60 dB).

    Beam Shaping

    To shape elliptical laser beams into round profiles, either an anamorphic prism pair (APP) or cylindrical lenses are used. The compressed circular beam is small enough for using inexpensive small-aperture isolators, and the fiber-coupling efficiency is enhanced by approximately 10 %. The compression ratio is set at the factory.

    Bias-T

    The DL pro (HP) has two modulation inputs that allow current modulation frequencies of up to 150 MHz. A Bias-T allows even higher current modulation frequencies of up to several GHz, depending on the diode. It is also suited for seed lasers of TA or NLO systems but not for DL pro HP lasers.

    Electronics Modules A broad variety of electronic locking modules is available for frequency stabilization.
  • Applications
    • Alkaline spectroscopy
    • Molecular physics
    • Gas sensing
    • Interferometry and holography
    • Optical communication
    • Magnetic-field measurement
    • Continuous-wave terahertz generation
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