Supercontinuum Generation for Frequency Metrology, Spectroscopy, or Optical Coherence Tomography Using Ti:sapphire, Nd(3+) Microchip or Nd(3+) Fiber Laser Pumps
Four-Wave Mixing and Self-Phase Modulation for Switching, Pulse-Forming and Wavelength Conversion Applications
Raman Amplification
These highly nonlinear photonic crystal fibers guide light in a small solid silica core surrounded by large air holes. The optical properties of these structures closely resemble those of a rod of glass suspended in air, resulting in strong confinement of the light and, correspondingly, a large nonlinear coefficient. By selecting the appropriate core diameter, the zero-dispersion wavelength can be chosen over a wide range in the visible and near infrared spectrum, making these fibers particularly suited to the generation of supercontinuum radiation with Ti:Sapphire or diode-pumped Nd(3+)- lasers, or for optical switching and signal processing applications.
λ0 is the zero dispersion wavelength for the nonlinear photonic crystal fibers.
a) Measured at λ0 b) Mode Field Diameter c) Numerical Aperture
The term supercontinuum generation includes many nonlinear effects that lead to a substantial spectral broadening. These nonlinear effects include Raman scattering, self-phase modulation and solitons. Supercontinuum spectra are typically produced by inputting short (femtosecond range) high power pulses into a nonlinear medium. Since the dispersion in a photonic crystal fiber can be tailored to facilitate the generation of supercontinuum spectra in a specific region, nonlinear photonic crystal fibers are an attractive media.
Supercontinuum (SC) sources are a new type of light source that combine the high radiant power and high degree of spatial coherence of a laser with a spectral bandwidth usually associated with an incandescent source. Supercontinuum sources can often drastically improve the signal-to-noise ratio, reduce the measurement time, or widen the spectral range in applications that require a broadband source, including high-resolution spectroscopy, the characterization of optical components, or optical coherence tomography (OCT). Despite the complex nature of the non-linear optical processes that convert the narrowband output of a laser into a supercontinuum, the practical realization can be surprisingly straight forward. All that is required is a high peak power pulsed laser, and a non-linear element with the right dispersion characteristics. The high power density, long length at comparatively low loss and the ability to achieve zero dispersion at wavelength shorter than 1250nm - something that is not achievable with conventional fibers - makes small-core PCF ideally suited as the nonlinear element in a SC source. Crystal Fibre offers small-core fibers suitable for use with femtosecond Ti:sapphire lasers (NLxx-xxx), as well as a fiber specifically designed to generate SC radiation from the output of a compact, low-cost Nd3+-YAG microchip laser (SC-5.0-1040). Please see detailed application notes linked below for more information.
When selecting a fiber for supercontinuum generation, the relationship between a fiber’s zero dispersion wavelength and the pump is the most important consideration. The table below provides a general guideline for cases when pumping the photonic crystal fiber with femtosecond laser sources. The attached pdf files offer more details regarding supercontinuum generation. One file is a general overview of supercontinuum generation and the other is focused on the SC-5.0-1040 PCF fiber.
Pump Wavelength
Output Spectrum
Below the zero dispersion wavelength
Stable, smooth and narrow spectrum
At the zero dispersion wavelength
Irregular, medium-wide and with a dip at the zero-dispersion wavelength
A response from Ken at Thorlabs to mathieu.perrin: Thank you for pointing out the error. The link has been fixed now.
Poster: mathieu.perrin
Posted Date: 2009-09-08 09:06:47.0
The stripping tab is buggy: the link to the application note is absent and there is a second set of tabs similar to those above.
Poster: rjr
Posted Date: 2009-04-16 13:54:45.0
Comments on Nonlinear PCF site:
1)In Features bullet list, second bullet should be 750 nm, not 850 nm
2)Next to Part Number, why does it say Imperial?
3)Several items removed from this list of NL fibers as of meeting April 15. Please see Carl Lin for details
4)Under Nonlinear PM Photonic Crystal Fibers, there is a fiber picture with some feature bullets. The picture and bullets pertain to fiber PM-1550-01 which is NOT a Nonlinear fiber, so it does not belong here.
5)In the table of Polarization Maintaining Nonlinear fibers, PM-NL-3.0-850 should be removed as it is not offered. The part P1-SC-5.0-FC-20 is also not offered. This long list should be updated to remove products not offered - recommend see Carl Lin
Polarization Beat Length at 1550 nm is typically <2 mm
DGD at 1550 nm is typically 2 ns/km
Nonlinear Coefficient 54 (W·km)-1 (cf 1.1 (W·km)-1 for SMF-28e+ at 1550 nm)
Near-Gaussian Mode Profile, Ellipticity of 1.13 at 830 nm
NKT Photonics' polarization-maintaining (PM) highly nonlinear photonic crystal fibers guide light in a small solid silica core, surrounded by a microstructure cladding formed by a periodic arrangement of air holes in the silica. The optical properties of the core closely resemble those of a slightly elliptical rod of glass suspended in air; this results in a strong confinement of the light, a large nonlinear coefficient, and a substantial splitting of the effective indices of the polarization modes. The zero-dispersion wavelength has been chosen for use with Ti:Sapphire laser sources, but the dispersion is also anomalous at the fundamental Neodymium wavelength (1060 nm).
The term supercontinuum generation includes many nonlinear effects that lead to a substantial spectral broadening. These nonlinear effects include Raman scattering, self-phase modulation and solitons. Supercontinuum spectra are typically produced by inputting short (femtosecond range) high power pulses into a nonlinear medium. Since the dispersion in a photonic crystal fiber can be tailored to facilitate the generation of supercontinuum spectra in a specific region, nonlinear photonic crystal fibers are an attractive media.
Supercontinuum (SC) sources are a new type of light source that combine the high radiant power and high degree of spatial coherence of a laser with a spectral bandwidth usually associated with an incandescent source. Supercontinuum sources can often drastically improve the signal-to-noise ratio, reduce the measurement time, or widen the spectral range in applications that require a broadband source, including high-resolution spectroscopy, the characterization of optical components, or optical coherence tomography (OCT). Despite the complex nature of the non-linear optical processes that convert the narrowband output of a laser into a supercontinuum, the practical realization can be surprisingly straight forward. All that is required is a high peak power pulsed laser, and a non-linear element with the right dispersion characteristics. The high power density, long length at comparatively low loss and the ability to achieve zero dispersion at wavelength shorter than 1250 nm - something that is not achievable with conventional fibers - makes small-core PCF ideally suited as the nonlinear element in a SC source. NKT Photonics offers small-core fibers suitable for use with femtosecond Ti:sapphire lasers (NLxx-xxx), as well as a fiber specifically designed to generate SC radiation from the output of a compact, low-cost Nd3+-YAG microchip laser (SC-5.0-1040). Please see detailed application note linked below for more information.
When selecting a fiber for supercontinuum generation, the relationship between a fiber’s zero dispersion wavelength and the pump is the most important consideration. The table below provides a general guideline for cases when pumping the photonic crystal fiber with femtosecond laser sources. The attached pdf file offers more details regarding supercontinuum generation using the NL series of Photonic Crystal Fiber.
Pump Wavelength
Output Spectrum
Below the zero dispersion wavelength
Stable, smooth and narrow spectrum
At the zero dispersion wavelength
Irregular, medium-wide and with a dip at the zero-dispersion wavelength
This application note addresses general handling of fibers from NKT Photonics, including how to strip the protective coating as well as how to cleave the fibers and tips for coupling light to and from the fibers. This is ideal for customers new to photonic crystal fibers.
The application note below addresses general advice about fusion splicing of photonic crystal fibers (PCFs). The note is limited to the work related directly to the fusion splicer, whereas guidelines for general handling of the PCFs can be found in the application note to the left.
A response from Ken at Thorlabs to jianminh: Unfortunately, according to the manufacturer, the current nonlinear fibers will not produce much supercontinuum energy down at these shorter wavelengths.
Poster: klee
Posted Date: 2009-10-20 16:10:30.0
A response from Ken at Thorlabs to jianminh: We are in contact with the manufacturer regarding this now. We will send you an email with more information shortly and also post it here.
Poster: jianminh
Posted Date: 2009-10-20 13:21:30.0
Hi, I hope to use the nonlinear photonic crystal fiber to generate wavelength shorter than 500nm laser,and the waveband width can reach to 25-30nm. Can your nonlinear photonic crystal fiber satify such requirement with Ti:sapphiere femtosecond laser pump. If its possible, can you give some advice to me.
Thank you very much.
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NL-1.7-700-02
- Highly Nonlinear PCF, 700 nm ZDW, 1.7 µm Core
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