Group Delay measurements of ultrabroadband pulses generated in highly nonlinear fibers
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-12-31 |
| Journal | Photonics Letters of Poland |
| Authors | Jan Szczepanek, Tomasz M. KardaĆ, Yuriy Stepanenko |
| Institutions | University of Warsaw, Polish Academy of Sciences |
| Citations | 1 |
| Analysis | Full AI Review Included |
Technical Analysis and Documentation for 6CCVD
Section titled âTechnical Analysis and Documentation for 6CCVDâExecutive Summary
Section titled âExecutive SummaryâThis paper investigates the complex temporal and spectral dynamics of ultra-broadband supercontinuum (SC) pulses generated in highly nonlinear Photonic Crystal Fibers (PCFs), a critical technology for developing stable, wide-spectrum light sources.
- Core Achievement: Successful measurement and analysis of Group Delay (GD) distribution in highly nonlinear fibers using the Cross-correlation Frequency Resolved Optical Gating (XFROG) technique.
- Key Finding: PCFs operating in the all-normal dispersion regime (NL-1050-NEG-1) yield smooth GD distributions, enabling compression to durations below 200 fs.
- Nonlinearity Management: PCFs crossing the Zero Dispersion Wavelength (ZDW) exhibit complex nonlinear effects (soliton fission, cross-phase modulation, Raman solitons), influencing stability and predictability.
- Polarization Control: Use of Polarization-Maintaining (PM) fibers achieved high Polarization Extinction Ratios (PER > 18 dB), crucial for integration into advanced fiber systems.
- Diamond Relevance (6CCVD Value Proposition): The literature cited explicitly identifies diamond as a superior solid-state medium for stable, ultra-broadband SC generation, leveraging its high damage threshold and inherent nonlinearity compared to the optical fibers studied.
- Methodology: Ultrafast 1030 nm pulses (12.6 MHz repetition rate, up to 52 nJ) were used to seed the PCFs, and the SC output was characterized using a 20 ”m thick BBO crystal for sum frequency generation.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the analysis of supercontinuum generation and characterization:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Seeding Pulse Center Wavelength | 1030 | nm | Generated by all-PM-fiber oscillator/amplifier system |
| Seeding Pulse Repetition Rate | 12.6 | MHz | System operating frequency |
| Compressed Pulse Duration (Input) | < 200 | fs | After standard grating compression |
| Maximum Seeding Pulse Energy | 52 | nJ | Prior to coupling into PCF |
| Fiber 1 (NL-NEG-1050-1) Length | 0.31 | m | All-normal dispersion PCF |
| Fiber 1 Max Output Energy | 14.3 | nJ | Broadened Supercontinuum |
| Fiber 2 (LMA-PM-5) Length | 1.16 | m | Zero Dispersion Wavelength (ZDW) PCF |
| Fiber 2 ZDW | ~1060 | nm | Point of dispersion zero crossing |
| Fiber 2 Max Output Energy | 8.9 | nJ | Broadened Supercontinuum |
| SC Output Spectral Range (Observed) | 600 - 1600 | nm | Dependent on fiber type and pump power |
| XFROG Crystal Thickness | 20 | ”m | Barium Borate (BBO) crystal, Type I |
| LMA-PM-5 Polarization Extinction Ratio (PER) | > 18 | dB | Maintained over full energy range |
| GD Standard Deviation (NL-NEG-1050-1) | 0.29 | ps | Measurement variation compared to datasheet calculation |
Key Methodologies
Section titled âKey MethodologiesâThe experimental setup relied on precise ultrafast optics components and highly controlled dispersion management to characterize the supercontinuum pulses.
- Seed Source Preparation: An all-PM-fiber oscillator and amplifier system generated ultrafast pulses centered at 1030 nm (12.6 MHz repetition rate). Pulses were compressed using a standard grating compressor to durations below 200 fs.
- Coupling and Generation: Seeding pulses (up to 52 nJ input, resulting in up to 14.3 nJ SC output) were coupled into two types of commercial Photonic Crystal Fibers (PCF):
- NL-1050-NEG-1 (All-Normal Dispersion): Coupled using an Aspheric Lens (AL, ~60% efficiency).
- LMA-PM-5 (ZDW at ~1060 nm): Coupled using a 10x microscope objective (~40% efficiency).
- XFROG Diagnostic Setup (Scheme shown in Fig. 3):
- The compressed seed pulse was split (10/90 Beam Splitter, BS). The 90% component seeded the PCF; the 10% component served as the ultrashort gate pulse for the delay line.
- The SC pulse and the gate pulse were synchronized and focused onto a 20 ”m thick BBO crystal for sum frequency generation (frequency mixing).
- The resulting sum frequency spectrum, varying with respect to the delay line position, was registered using an Ocean Optics USB4000 spectrometer (177-895 nm span).
- Polarization Control: Half-wave plates (λ/2) and polarizers (POL) were used to align the linear polarization of the seed light to the PM fiber axis and to measure the Polarization Extinction Ratio (PER) of the resulting supercontinuum pulses.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research reinforces the requirement for materials capable of handling high peak power, exhibiting high nonlinearity, and offering precise dimensional control for ultrafast optics integration. 6CCVDâs MPCVD diamond is the ideal replacement and upgrade path for future solid-state supercontinuum sources, particularly where stability and damage threshold are paramount.
Applicable Materials
Section titled âApplicable MaterialsâThe paper highlights the use of solid-state media (including diamond [2]) for ultra-broadband SC generation. 6CCVD supplies materials that offer significant advantages over current fiber or thin BBO crystal systems in terms of nonlinearity, thermal management, and damage resistance.
| 6CCVD Material | Relevance to Ultrafast/SC Research | Customization Potential |
|---|---|---|
| Optical Grade Single Crystal Diamond (SCD) | Highest intrinsic optical damage threshold and broadest transparency (UV to far-IR). Ideal for high-power, high-stability SC generation, replacing bulk crystals or specialty fibers. | Thicknesses available from 0.1 ”m up to 500 ”m, perfectly suited for highly nonlinear thin films or ultra-thin optical windows. |
| Polycrystalline Diamond (PCD) Wafers | Excellent thermal conductivity for active thermal management of high-power laser systems and amplifiers (relevant to the 1030 nm pump source). | Wafers up to 125 mm diameter available for complex heat spreader integration and device packaging. |
| Boron-Doped Diamond (BDD) | Potential for integrated electro-optic modulation or advanced photoconductive switching within the amplifier or diagnostic stages. | Custom doping levels and thicknesses available. |
Customization Potential
Section titled âCustomization PotentialâThe experiment utilized a 20 ”m thick BBO crystal, demanding extremely precise dimensional control for nonlinear mixing. 6CCVD excels in providing thin, highly polished diamond components.
- Precision Thin Films: 6CCVD offers SCD films polished down to 0.1 ”m thickness, surpassing the mechanical and thermal stability of thin BBO. This is critical for maximizing nonlinear effects while minimizing group velocity dispersion.
- Ultra-High Polishing: For integrating into PM systems requiring high PER, SCD wafers are polished to an exceptional surface roughness of Ra < 1 nm. Inch-size PCD wafers can achieve Ra < 5 nm.
- Advanced Metalization: While the current setup is purely optical, integration of SCD into photonic systems often requires contacting or bonding layers. 6CCVD offers in-house custom metalization stacks including Ti/Pt/Au, Pd, W, and Cu, allowing for direct integration into semiconductor or high-power packaging platforms.
- Custom Dimensions: Laser cutting services enable production of custom-geometry optical elements required for precise coupling, polarization control, or sensor integration, moving beyond standard wafer sizes.
Engineering Support
Section titled âEngineering SupportâGenerating stable, high-quality ultra-broadband light sources using non-fiber materials (like diamond) requires optimizing crystal orientation, thickness, and surface preparation. 6CCVDâs in-house PhD team provides expert consultation on:
- Material Selection: Guiding researchers in choosing the optimal diamond grade (SCD vs. PCD) and orientation for high-efficiency Supercontinuum Generation or Frequency Mixing applications.
- Thermal Modeling: Assisting in designing diamond thermal substrates for high-power ultrafast Amplifier Systems (1030 nm source).
- Dispersion Management: Advising on crystal thickness and polishing requirements to minimize detrimental dispersion effects in advanced nonlinear optical components.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. Global shipping is available (DDU default, DDP option).
View Original Abstract
Ultra broadband supercontinuum pulses are commonly used as a source of different wavelengths from a wide spectral bandwidth or as a source of very short pulses. However the processes responsible for wide spectral broadening are still under investigation. In this paper we examine the temporal and spectral characteristics of the pulses broadened upon propagation in the highly nonlinear photonics crystal fibers with different dispersion profiles. Generated supercontinuum pulses were experimentally characterized using cross-correlation frequency resolved optical gating technique. Full Text: PDF ReferencesM. Bradler, P. Baum, and E. Riedle, âFemtosecond continuum generation in bulk laser host materials with sub-?J pump pulsesâ, Appl. Phys. B 97, 561 (2009). CrossRef T. M. Kardas, B. Ratajska-Gadomska, W. Gadomski, A. Lapini, and R. Righini, âThe role of stimulated Raman scattering in supercontinuum generation in bulk diamondâ, Opt. Express 21, 24201 (2013). CrossRef A. Brodeur and S. L. Chin, âBand-Gap Dependence of the Ultrafast White-Light Continuumâ, Phys. Rev. Lett. 80, 4406 (1998). CrossRef R. R. Alfano, ed., The Supercontinuum Laser Source: Fundamentals with Updated References, 2nd ed (Springer, 2006). DirectLink A. L. Gaeta, Phys. âCatastrophic Collapse of Ultrashort Pulsesâ, Rev. Lett. 84, 3582 (2000). CrossRef J. M. Dudley, G. Genty, and S. Coen, âSupercontinuum generation in photonic crystal fiberâ, Rev. Mod. Phys. 78, 1135 (2006). CrossRef M. Klimczak, B. Siwicki, P. Skibinski, D. Pysz, R. Stepien, A. Heidt, C. Radzewicz, and R. Buczynski, âCoherent supercontinuum generation up to 2.3 ?m in all-solid soft-glass photonic crystal fibers with flat all-normal dispersionâ, Opt. Express 22, 18824 (2014). CrossRef D. J. Kane and R. Trebino, âCharacterization of arbitrary femtosecond pulses using frequency-resolved optical gatingâ, IEEE J. Quantum Electron. 29, 571 (1993). CrossRef J. Dudley, X. Gu, L. Xu, M. Kimmel, E. Zeek, P. OâShea, R. Trebino, S. Coen, and R. Windeler, âCross-correlation frequency resolved optical gating analysis of broadband continuum generation in photonic crystal fiber: simulations and experimentsâ, Opt. Express 10, 1215 (2002). CrossRef N. Nishizawa and T. Goto, âExperimental analysis of ultrashort pulse propagation in optical fibers around zero-dispersion region using cross-correlation frequency resolved optical gatingâ, Opt. Express 8, 328 (2001). CrossRef X. Gu, L. Xu, M. Kimmel, E. Zeek, P. OâShea, A. P. Shreenath, R. Trebino, and R. S. Windeler, âFrequency-resolved optical gating and single-shot spectral measurements reveal fine structure in microstructure-fiber continuumâ, Opt. Lett. 27, 1174 (2002). CrossRef S. Roy, S. K. Bhadra, and G. P. Agrawal, âEffects of higher-order dispersion on resonant dispersive waves emitted by solitonsâ, Opt. Lett. 34, 2072?2074 (2009). CrossRef S. Bose, S. Roy, R. Chattopadhyay, M. Pal, and S. K. Bhadra, âExperimental and theoretical study of red-shifted solitonic resonant radiation in photonic crystal fibers and generation of radiation seeded Raman solitonâ, J. Opt. 17, 105506 (2015). CrossRef T. Roger, M. F. Saleh, S. Roy, F. Biancalana, C. Li, and D. Faccio, âHigh-energy, shock-front-assisted resonant radiation in the normal dispersion regimeâ, Phys. Rev. A 88, (2013). CrossRef G. P. Agrawal, Nonlinear Fiber Optics, Fifth edition (Elsevier/Academic Press, 2013). DirectLink J. Szczepanek, T. Kardas, M. Nejbauer, C. Radzewicz, and Y. Stepanenko, âSimple all-PM-fiber laser system seeded by an all-normal-dispersion oscillator mode-locked with a nonlinear optical loop mirrorâ, Proc. SPIE 9728, 972827 (2016). CrossRef C. Iaconis and I. A. Walmsley, âSelf-referencing spectral interferometry for measuring ultrashort optical pulsesâ, IEEE J. Quantum Electron. 35, 501 (1999). CrossRef L. E. Hooper, P. J. Mosley, A. C. Muir, W. J. Wadsworth, and J. C. Knight, âCoherent supercontinuum generation in photonic crystal fiber with all-normal group velocity dispersionâ, Opt. Express 19, 4902 (2011). CrossRef J. Szczepanek, T. M. Kardas, and Y. Stepanenko, âSub-160-fs pulses dechriped to its Fourier transform limit generated from the all-normal dispersion fiber oscillatorâ, Optical Society of America Frontiers in Optics conference, FTu3C?2 (2016). CrossRef G. Genty, M. Lehtonen, and H. Ludvigsen, âEffect of cross-phase modulation on supercontinuum generated in microstructured fibers with sub-30 fs pulsesâ, Opt. Express 12, 4614 (2004). CrossRef S. Roy, S. K. Bhadra, K. Saitoh, M. Koshiba, and G. P. Agrawal, âDynamics of Raman soliton during supercontinuum generation near the zero-dispersion wavelength of optical fibersâ, Opt. Express 19, 10443 (2011). CrossRef Y. Liu, Y. Zhao, J. Lyngso, S. You, W. L. Wilson, H. Tu, and S. A. Boppart, âSuppressing Short-Term Polarization Noise and Related Spectral Decoherence in All-Normal Dispersion Fiber Supercontinuum Generationâ, J. Light. Technol. 33, 1814 (2015). CrossRef