+1/-1 order phase masks
Easy and cost-effective fabrication of Bragg gratings
Ibsen’s +1/-1 order principle phase masks ensure quality and facilitate production in the telecommunications, sensor, and laser industries. In the production of fiber and waveguide Bragg gratings, the phase mask is illuminated by a laser. Self-interference between the diffracted first orders produces the required pitch in the fiber or waveguide.
Any deviation from the desired grating structure in the Phase mask is transferred directly to the fiber or waveguide. It is therefore imperative that the Phase mask pitch is accurate, uniform, and defect-free. Through scientific principles and constants of nature, our fabrication process ensures absolute pitch accuracy. In addition, geometric principles in our production equipment ensure strict uniformity, eliminating e-beam drawbacks such as stitching errors and field distortion.
Other important features of our line of +1/-1 order Phase masks are:
Key benefits

+1/-1 order principle
Using the +1/-1 order principle, the phase mask is optimized to diffract light equally and maximally into the plus first and minus first orders. Self-interference between these two orders creates an interference pattern with half the pitch of the phase mask pitch. As the diagram illustrates, a +1/-1 order phase mask can generate additional unwanted orders. Ibsen phase masks have highly suppressed zero order noise. The main advantage of this +1/-1 order principle (relative to the 0/-1 order principle) is its ease of use with normally incident illumination.
Documentation

Product range and specifications
Parameter | Specification |
---|---|
Grating periods | 260 nm - 2650 nm |
Illumination wavelengths | 193 nm - 1065 nm |
Material | UV grade fused silica |
Period accuracy | +/- 0.01 nm |
Period uniformity | +/- 0.01 nm |
Chirp rates | 0 - 30 nm/cm |
Standard grating sizes | 10 mm x 10 mm 25 mm x 10 mm 50 mm x 10 mm 100 mm x 10 mm |
Guaranteed 0. order suppression | <3% (lower spec optional) |
Typical 0. order suppression | 0-2 % |
0. order uniformity | |
Grating length 10 mm | +/- 0.5 % |
Grating length 25 mm | +/- 0.75 % |
Grating length 50 mm | +/- 1.0 % |
Grating length 100 mm | +/- 1.5 % |
Ibsen as your grating manufacturer
At Ibsen Photonics, we recognize that the optical grating is a mission-critical component in your device or instrument – where performance and reliability are non-negotiable.
As an ISO 9001 and 13485 certified manufacturer, we bring decades of expertise in both prototyping and high-volume production of transmission gratings. Our focus is unwavering: to deliver superior, consistent quality.
Our commitment is backed by robust, proven designs, 100% metrology on diffraction efficiency, and comprehensive outgoing inspection. The result? Over hundreds of thousands of gratings deployed in the field – without a single reliability failure or return.
We maintain stable supply chains through long-standing partnerships with qualified sub-suppliers and offer flexible delivery models tailored to OEM needs, including frame orders and Kanban agreements.
Partnering with Ibsen means you can rely on a trusted, experienced grating supplier – so you can stay focused on advancing your core technology.
Advantages working with Ibsen:
Which phase mask to use?
For further information or to request a quotation please contact us.