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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.

  • Specifications
    DFB proDFB pro LDFB pro BFY
    Center wavelengths633 nm, 760 nm - 3500 nm1064 nm .. 2000 nm *
    Output power2 .. 150 mW 10 .. 100 mW (fiber output)
    Tuning range2 .. 6 nm 2 .. 5 nm, mode-hop free
    Thermal tuning
       Typical range> 1000 GHz > 600 GHz
       Typical speed50 GHz / sec 25 GHz / sec
       Typical rate-25 GHz / K -10 .. -15 GHz / K
    Electric tuning   
       Typical range50 GHz > 25 GHz
       Typical speedUp to MHz frequencies Up to MHz frequencies
       Typical rate1 .. 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 characteristicsCollimated, 3 mm x 1 mm (circular with Beam shaping / pro)Circular, divergent, Fiber NA typ. 0.12
    Output beam polarizationLinear, > 100:1 Linear, typ. 100:1
    Fast modulation
    (AC and DC coupled)
    IncludedIncludedIncluded
    Beam shaping / proOptionalOptional--
    Optical isolatorsOptional, 30 dB **Optional, 30 dB or 60 dBIncluded ***
    Fiber couplingSmartDock, optionalFiberDock, optionalFiber 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 kg3 kg1 kg
    Typical wavelengths633 nm780 / 795 nm1178 nm (butterfly)
     780 / 795 nm852 / 895 nm1.5 µm
     852 / 895 nm1000-1100 nm1.65 µm
     > 2 µm (free-beam, w/o isolator)1178 nm2 µm (butterfly)
    Dimensions control unit (H x W x D)150 x 465 x 385 mm (19" rack) 
    Weight control unit8 kg 
    Operating voltage100 .. 240 V~, 50/60 Hz (wide range input) 
    Power consumptionTyp. < 100 W, max. 300 W 
    PC InterfaceUSB (only in systems with DigiLock) 
    Environmental temperature15 - 30 °C (operating), 0 - 40 °C (storage and transport)
    Environmental humidityNon 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 ModulesA 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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