Toptica Difference Frequency Comb (DFC) Inherently CEP-stable modular frequency combs

frequency combs

TOPTICA’s frequency comb product line is a modular system that supports a broad variety of applications. Three basic versions of the DFC are available: DFC CORE, DFC CORE+ and DFC SEED. All models use TOPTICA proprietary CERO-technology to achieve an unprecedented low-noise performance.

The DFC CORE and its high performance version DFC CORE+ come with a digital oscilloscope for beat monitoring and a GPS disciplined RF reference included. They both provide 4 or optionally 8 phase-stable outputs at 1560 nm.

Several extension modules are available that can convert the DFC CORE / DFC CORE+ outputs to any wavelength between 420 nm and 2200 nm. The extension modules can be upgraded at any time after purchase of the DFC CORE and are interchangeable between outputs.

In addition, beam combiner (DFC BC) and beat detector (DFC MD) units are available to provide RF beats between the DFC comb lines and cw lasers. The RF output signal of the DFC MD can be counted to determine the frequency of the cw laser. It also enables phase or frequency stabilization of the cw laser to the DFC using e.g. TOPTICA’s locking modules mFALC or DigiLock. In the DFC CORE+ version, the RF output signal can also be used to stabilize the DFC to the cw laser which serves as optical reference.

Such a DFC system can be combined with any of TOPTICA’s tunable diode lasers to achieve a complete, frequency referenced laser system including wavelength meter and counter all from one source.

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Toptica DFC CORE / DFC CORE+ Low-noise frequency comb


  • Based on mode-locked Erbium fiber laser
  • Offset-free by difference frequency generation
  • Patented CERO (“zero-fCEO”) technology
  • CORE unit with 4 or 8 outputs at 1560 nm
  • Optional extensions for frequency conversion

The CORE unit of TOPTICA’s Difference Frequency Comb (DFC) consists of a low noise mode-locked oscillator, a fiber-optic amplifier, a nonlinear fiber for supercontinuum generation, a CERO unit for difference frequency generation (DFG) and a fiber-optic pre-amplifier. The DFC CORE provides 4 or 8 fCEO-stabilized outputs at 1560 nm. Each output can seed a user-defined extension as specified on the DFC Extensions section. It comes with integrated radio frequency reference and dedicated frep locking electronics. A beat monitoring unit comprising a laptop and a digital scope with spectrum analyzer mode allows for convenient monitoring and analysis of locking beats.

Download brochure here.

Toptica DFC SDL Frequency-comb-stabilized laser system


  • Rack-mounted
  • Complete, stabilized laser systems
  • Up to 8 cw-outputs between 420 - 2200 nm
  • One central software
  • Transportable

TOPTICA's offset-free frequency comb DFC (Difference Frequency Comb) and tunable cw diode lasers (DL pro) can be combined into easy-to-use laser systems delivering frequency-stable cw-output at any wavelength between 420 nm and 2200 nm. A complete laser system contains a DFC CORE, wavelength extensions (DFC EXT), cw diode lasers (DL pro), beat units (DFC BC, DFC MD), all necessary stabilization electronics, a wavelength meter (High Finesse), RF-reference, counter, spectrum analyzer, control server (PC) and user software.

All these components can now be integrated into a single transportable 19-inch rack. The standard system comes with two frequency stable cw-outputs and all required accessories. The control software runs on an integrated PC acting as server, it can be operated remotely using the client GUI. The laser frequencies can be set manually within the comb extension and DL pro bandwidth and are displayed live by the software.

Download pdf Product Brochure here.

Toptica DFC SEED Low-noise OPCPA seeder


  • Intrinsic CEP stability by DFG method (CERO)
  • 8 mrad RMS phase stability in 20 s
  • Best commercially available CEP-stability
  • Long-term CEP drifts can be compensated
  • Dual synchronized output at 1560 nm and 1030 nm or 1950 nm

The DFC SEED unit is dedicated for OPCPA and high power amplifier seeding that require phase-stable ultrashort laser pulses at 1560 nm and 1030 nm or 1950 nm. It combines an outstanding passive CEP stability which challenges the best Ti:sapph lasers with the convenience and robustness of a fiber laser. Long-term drifts of the CEP that are caused by a subsequent amplifier chain can be compensated through a dedicated feedback channel. The repetition rate frep of the DFC SEED can be synchronized to any appropriate reference.

Download detailed brochure here.

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