SETTING NEW STANDARDS WITH T-DCF
Phone
+358 40 7054772
T-DCF: The Basis of Ultrafast Fiber Laser Performance
Our mission is to enable widespread adoption of fiber laser-based micromachining and material processing technology by providing cost-effective and high-performance sources of ultrashort laser pulses. This is made possible by our patented, unique T-DCF technology, developed by Dr. Valery Filippov and Prof. Yuriy Chamorovskiy, enabling high-performance ultrafast fiber laser systems. This makes Ampliconyx a pioneer in this field as we are the only company worldwide offering fiber-based amplifier modules and laser systems from kW to MW peak power.
What Exactly Is T-DCF and How Does It Work?
T-DCF is an optical fiber with a core doped by rare-earth elements (Yb, Er, Tm etc.) and is exploited as a gain element in high power amplifiers, both CW and pulsed. Core and cladding diameters of T-DCF are smoothly increasing along the length ensuring strictly singlmode light propagation at narrow part and supporting near singlemode propagation at highly multimode wide part. Usually the core/cladding parameters (diameter and numerical aperture) are chosen such that fundamental mode only is supported at the narrow part of T-DCF.
At the wide end, a T-DCF has a substantially larger core diameter (typically within range 50 to 100 μm), while the mode content and beam quality (M2) remains almost the same as it was in the narrow side. Thus, in the active T-DCF, a unique situation is realized where only the fundamental mode propagates in the core, despite hundreds of modes potentially being able to exist. Hence, the tapering of the active fiber allows achieving an excitation and propagation of fundamental mode only in a multimode core with a diameter of several tens of microns.
Key Advantages of
Active T-DCF
- Large mode field diameter (up to 100 μm), resulting in a significantly increased threshold for nonlinear effects (SRS, SPM) in fiber lasers and amplifiers;
- High cladding pump absorption (typically >20 dB) allows for shorter amplifier active media, further increasing the threshold for nonlinear effects compared with conventional fibers;
- Immunity to the stimulated Brillouin scattering (SBS) due to an increase in the core/cladding diameter
Patents & Intellectual Property
FAQ – Frequently Asked Questions
What fundamentally differentiates an active Tapered Double Clad Fiber (T-DCF) from conventional LMA and single-mode fibers?
An active T-DCF features a longitudinal taper where the core and cladding dimensions smoothly expand along the fiber’s length. By launching seed light into the narrow single-mode end, solely fundamental mode excitation (LP01) is established and maintains this beam quality (M2) even as the core expands up to 50–100 µm at the wide end. This large output core provides an effective mode field diameter (MFD up to 70 – 80 µm) that significantly elevates the threshold for nonlinear effects like SPM and SRS without suffering from higher-order mode excitation or thermal mode instability typical of standard LMA fibers. Additionally, high pump absorption in the tapered geometry allows for shorter fiber lengths, while the core diameter change naturally mitigates Stimulated Brillouin Scattering (SBS).
Which applications benefit most from T-DCF technology
T-DCF technology benefits applications requiring ultra short pulses, high peak power, high pulse energy, and diffraction-limited beam quality without complex free-space amplification stages. Key sectors include ultrafast industrial micromachining and semiconductor processing, where clean high-repetition-rate picosecond or nanosecond pulses are required without nonlinear pulse distortion. Medical biophotonics, multiphoton imaging, LiDAR/sensing systems, and defense platforms also leverage T-DCF for robust, compact, and high-brightness all-fiber architectures. Furthermore, scientific research and quantum photonics utilize T-DCF modules as efficient source of light for frequency conversion and quantum applications.
How easily can T-DCF amplifiers be integrated into existing architectures?
T-DCF amplifiers are designed as modular, ready-to-use, all-fiber components that seamlessly integrate into standard master oscillator power amplifier (MOPA) setups. The narrow input end connects directly to standard single-mode seed lasers via conventional fiber splicing, eliminating the need for complex alignment or free-space coupling optics. Turnkey gain modules incorporate integrated pump multiplexers and thermal management, providing a plug-and-play upgrade path for existing fiber laser systems. This streamlined integration minimizes optical losses, reduces assembly footprint, and lowers overall development time for system integrators.
To what extent can T-DCF geometry and parameters be customized within the existing IP framework?
The patented T-DCF framework (US Patent 8,433,168 B2) allows extensive customization of key structural parameters tailored to specific user requirements. Customizations include tuning the core and cladding taper ratios, longitudinal taper profiles, total fiber length, and rare-earth dopant concentrations (such as Yb, Er, or Tm). Additionally, parameters such as numerical aperture (NA), polarization-maintaining (PM) structures, and specific input/output core diameters can be engineered to match unique seed source specifications. This flexibility ensures target performance metrics – such as specific spectral bands, pulse durations, or power levels – are fully optimized within the established IP boundaries.
What lifetime performance metrics are available for active T-DCF
Active T-DCF modules undergo rigorous qualification testing demonstrating long-term power stability, spectral consistency, and high degradation resistance under continuous high-power operation. Tests show minimal power drop and stable single-mode beam quality (M2~1.1) across thousands of operational hours. The all-fiber silica structure inherently eliminates alignment drift, degradation from atmospheric contamination, and mechanical misalignment common in bulk optics. Detailed test reporting – including optical efficiency retention, photodarkening resistance, and thermal cycle durability – can be provided upon request for high-reliability OEM applications.
Discover the Potential of T-DCF Technology
Interested in how T-DCF can improve your laser architecture? Our experts are ready to discuss your application requirements and explore how Ampliconyx technology can support your next-generation laser system.
info@ampliconyx.com
