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Long Phase Mask

120 mm long aperture
Holographically recorded
Linearly chirped

StockerYale’s Long Phase Mask has a 120 mm long grating and is ideal for applications such as dispersion compensation and dense wavelength division multiplexing (DWDM). Our proprietary holographic recording method also eliminates “stitching errors”, which are a cause of side lobes.

Typical FBG applications:

Dispersion compensation gratings (DCGs)
DWDM
Narrow bands filters

Technical Specifications

Operating wavelength:	190 - 400 nm

Phase mask period:	0.6 - 1.2 µm

Period manufacturing tolerance	± 0.3 nm for unchirped masks (± 0.1 nm optional)

Period measurement accuracy:	± 0.02 nm

Dimensions	Substrate size / Aperture 17.2 x 127.0 mm / 10 x 120 mm 17.2 x 152.4 mm / 10 x 140 mm

Chirp range (for chirped masks)	0.03 nm/cm - 30 nm/cm

Diffraction Efficiency	≤5% in 0th order; ≥30% in ±1st order

Damage threshold	Better than 1 J/cm2 perpulse at 50 Hz @ 248 nm

Material	λ @ 248 nm, both sides

Substrate flatness	< 2 µm TIR, both sides

Scratch & Dig	20 - 10

AR coating	Optional

Wedge	< 30 arcsec

Thickness	3.175 mm ± 0.125 mm

For chirped masks; center period precision ± 0.5 nm with ± 200 µm center positioning error

Ordering Information

LPM (LPMC if chirped) - <wavelength of laser> - <mask period> - <(grating dimension (W x L)) substrate dimension (W x L)>

Example: a 15mm x 127mm dimension phase mask to be used with a KrF excimer laser at 248 nm with a period of 1.0600 µm, is specified as:
LPM - 248 - 1.0600 (10 x 120) 17.2 x 127

Example for 0.083 nm/cm chirped mask:
LPMC - 248 - 1.0600 - (10 x 120) 17.2 x 127 - 0.083 nm/cm