Fiber Gratings

Fiber Gratings

We have the capability to fabricate Fibre Bragg Gratings (FBGs) and Long-Period Gratings (LPGs). An in-house designed Fibre Grating Fabrication System with sophisticated software for fabrication process control has been setup allowing various types of

1. Fiber Bragg Gratings (FBGs) & Long Period Gratings (LPGs)

A fibre grating is a region of fibre whose refractive index has been permanently modified by exposing to light. Such exposure, if carried out with an interferometer or phase mask, allows a periodically varying refractive index grating or pattern to be “written” into the core of optical fibre. These “in-fibre” components are spectrally selective, which allow only specific wavelengths to be reflected or rejected, and are thus suitable for performing many tasks such as filtering and reflecting, in a highly efficient, low loss manner.

We have the capability to fabricate Fibre Bragg Gratings (FBGs) and Long-Period Gratings (LPGs). An in-house designed Fibre Grating Fabrication System with sophisticated software for fabrication process control has been setup, allowing various types of fibre gratings to be fabricated including complex grating structures such as Moiré, sampled, chirped and phase shift gratings. For the first time, we have also demonstrated the possibility of directly writing gratings on an optical fibre coated with standard off-the-shelf coating, with the resulting reflectivity and index change found to be equivalent to that of a fibre grating fabricated with bare fibre.

Our FBG system can make gratings with typical characteristics:

  • wavelength response is mainly in C band and L band;
  • depth can be higher than 30dB;
  • bandwidth is around 0.5-1 nm, depending on the depth of grating.
  • simple recoating

Applications

  • Notch filters
  • Optical multiplexers and demultiplexers
  • Optical circulators
  • Optical add-drop multiplexers (OADM)
  • Fiber Grating sensors sensitive to strain and temperature
  • FBGs used as reflectors in fiber lasers to make cavities

We can also fabricate customized fiber gratings! We are also open to heavily customised gratings, like tilted gratings or chirped gratings. Just let us know your requirements and the details in the ordering information below.

Ordering information:

  • Wavelength
  • Grating pitch
  • Depth
  • Bandwidths and tolerences
  • Chirp
  • Simple recoating

2. Gain Flattening Filters for C- and L- bands

  • Customized gain flattening profiles
  • Wide bands from 1520 nm to 1570 nm or 1560 nm to 1610 nm
  • Low ripple
  • Low insertion loss
  • Athermal packaging
  • High strength and reliability

fiber gratings

Wavelength Range for C-band 1520 to 1570 nm
Wavelength Range for L-band 1560 to 1610 nm
Maximum Attenuation 8 dB or more on request
Attenuation Accuracy < ± 5% of attenuation
Insertion Loss < 0.5 dB
Operational Temperature Range 0 - 70° C
Fiber SMF-28 compatible, 1 meter
Package Dimensions 6.4 mm diameter x 64-95 mm L

3. Fiber Gratings for Laser Resonators and Sensors

  • Customized design
  • Variety of wavelengths
  • Optimized reflectivity and bandwidth
  • High strength and reliability
Wavelength Accuracy < ±0.5 nm
Reflectivity 1 to 99.9 %
3-dB Reflection Bandwidth 0.2 to 1 nm
Grating Profile Uniform or apodized
Insertion Loss < 0.1 dB
Fiber Corning SMF-28 (other fiber types available)
Recoating Acrylate or custom
Pulling Strength > 100 kpsi

4. 50 / 100 GHz DWDM Gratings

  • Near-square reflection spectral response
  • Optimized for 50 GHz or 100 GHz channel spacing
  • High center wavelength accuracy
  • Low channel crosstalk
  • Low insertion loss
  • Athermal package
  • High strength and reliability

fiber gratings

50 GHz 100 GHz
Center Wavelength and Accuracy on ITU grid offset < ± 0.05 nm*
Cladding Mode Loss < 0.5 dB
Reflection > 99.9 %
Bandwidth 50 100 GHz
Bandwidth - 0.5 dB Reflection Bandwidth > 0.2 > 0.3 nm
Bandwidth -30 dB Transmission Bandwidth > 0.1 > 0.15 nm
Adjacent Channel Crosstalk < - 25** < - 30 dB
Non-adjacent Channel Crosstalk < - 30 < - 30 dB
Insertion Loss > 0.2 dB
Thermal Sensitivity < 0.5 pm/°C
Operational Temperature Range 0 - 70 °C
Fiber SMF-28 compatible
Package Dimensions 6.4 mm f × 55 mm L mm
  • * With package only
  • ** 50 GHz gratings with adjacent channel crosstalk < -30 dB can be supplied on request

5. Athermal Package for Fiber Bragg Grating Devices

We offer an athermal package option to compensate for the thermal sensitivity of Fiber Bragg Grating devices

  • 0 to 70 °C operating range
  • < 30 pm drift over operating range
  • Small size (6.35 mm O.D.)
  • Permanent identification marking
  • Plain or jacketed SMF-28 compatible fiber leads