Femtosecond Fiber

FemtoFiber technology for ultrafast lasers

The engine of TOPTICA‘s fiber lasers is a SAM mode-locked ring oscillator. This configuration – protected by an optical isolator – is known to be most robust against back reflections of any kind. This high stability of the mode-locking is caused by operating in the solitonic regime. Special TOPTICA design ensures full suppression of parasitic pedestals (Kelly-bands). The soliton pulses are carefully amplified to very high peak powers in a subsequent core-pumped fiber amplifier. This MOPA (Master Oscillator Power Amplifier) platform is an all-fiber setup based completely on polarization-maintaining fibers. By using Erbium and Ytterbium doped fibers, TOPTICA provides these advantages of fiber lasers for two fundamental wavelength regions around 1560 nm (Er) and 1030 - 1064 nm (Yb).

The FemtoFiber series, using SAM mode-locking technique and polarization-maintaining fiber technology, are forming TOPTICA's state-of-the-art ultrafast fiber laser series. With diode pumped all-fiber oscillator and amplifier designs without any free beam sections, a new breakthrough concerning robustness, reliability and long-term stability could be achieved. Furthermore, a hands-off one-button design allows these lasers to be used in various new applications such as life sciences, attoscience, optical coherence tomography, time-domain terahertz - even towards industrial/OEM integration.

The fiber oscillators of the FemtoFiber lasers may be used for seeding either one or more optical amplifiers. Synchronized multiple laser systems are highly beneficial in applications like frequency metrology and pump-probe experiments. Several options further extend the scope of the scientific series of the FemtoFiber lasers. These include frequency conversion extensions and options for synchronizing the laser pulses to other pulsed sources.

Fiber Laser Advantages

Good Reasons to Change from Solid State to Fiber Technology

FiberSolid State
Long gain medium: efficientShort gain medium: inefficient
Cool fiber: excellent thermal propertiesConcentrated pump power: hot crystal, thermal lensing
Guaranteed overlap inside fiber, always perfectly alignedCritical overlap of pump light and oscillator path, easily misaligned
Single-mode fiber guarantees diffraction limited mode profile

Mode profile depending on pump laser profile and cavity alignment

FemtoFiber: Telecom reliabilityFemtoFiber vs. Ti:Sa Laser
Telecom components, reliable and economicalExpensive components
Robust and shock-proofFragile optics
Small, portable, quietBulky, with additional pump laser and noisy chiller
Maintenance freeRegular maintenance

Price and System Size

  • Cost-effective & low cost of ownership
  • Compact footprin
  • Neither air nor water cooling required


  • Reliable SAM technology
  • Self-starting mode-locking

SAM Mode-Locking Technology

The saturable absorber mirror (SAM) ensures self-starting and reliable mode-locking. This passive device efficiently suppresses Q-switching operation. Only intense solitonic laser pulses are stabilized and supported by the SAM.

PM fiber Technology

Polarization-maintaining (PM) fibers preserve the linear state of polarization under all circumstances: Temperature, mechanical stress, humidity or other environmental influences can‘t disturb the stable laser operation.

24/7 robust operation

  • PM fiber assembly
  • All-fiber: Alignment-free
  • Telcordia proven components