Location

NATSUME OPTICAL CORPORATION has been researching and developing high-precision glass optics in a wide variety of shapes and forms since our establishment in 1947 in Nagano, Japan.

With the semiconductor filed

In the semiconductor field, which we entered in the 1980s, our challenging spirit and tenacity have led us to achieve the world’s most advanced LIGHT technology.

Our facilities

Our Technology Center is equipped with MRF polishing machines, world-leading measurement instruments with nanometer precision, and Class 1000 cleanrooms.

HSFR: Extreme low

For beyond EUV optics, high-spatial-frequency roughness (HSFR) must be low to improve damage tolerance and prevent scattering. Using our proprietary technology, we can offer extremely low HSFR surfaces characterized by

• RMS down to 0.1 nm and below.
• Free form including off-axis ellipsoid.
• Material from Silicon, Fused Silica, CaF2 and others.
• Qualified by white light interferometer and AFM.

MSFR: Below 0.10 nm

Roughness in the spatial frequency range of 1/0.01 - 1 mm is defined as mid-spatial-frequency roughness (MSFR). MSFR causes unwanted intensity distribution in beam transportation or focusing. We can provide extremely low MSFR surfaces characterized by

• RMS down to 0.1 nm in an area of 1 mm × 1 mm.
• Processed by high-spatial-resolution polishing.
• Qualified by white light interferometer.

Our optics are highly regarded in the semiconductor industry for their extremely low MSFR.

Slope error: From 0.1 μrad

In EUV and X-ray optics in focusing systems, figure error is an important factor in achieving small focus sizes. Our free-form optics have extremely low figure error, which we consider to be the best surface quality in the world.

• Slope error: 0.1 - 0.5 μrad RMS.
• Figure error: 0.3 nm RMS (2 nm for steeply curved free-form)
• Off-axis ellipsoid, Wolter, and others.
• High-precision enough to use at synchrotron
　
• radiation facilities.

High-efficiency focusing

In addition to high-precision mirrors and lenses, we manufacture electroformed mirrors with various internal freeform reflective surfaces. These mirrors are used in focusing systems for laboratory-scale experiments, commercial microscopy platforms, and synchrotron radiation facilities.

• Submicron-level focusing for photoemission spectroscopy, scanning transmission microscopy, imaging systems, etc.
　
• High efficiency, low scattering, millimeter-range working distance
　
• Fully rotationally symmetric freeform surface
　
• Φ5 - 20 mm, L40 - 100 mm surface roughness: 0.3 - 0.4 nm RMS.

For DUV field

Material for prisms

• CaF2
• MgF2
• Fused Silica

Material for plates

• Quartz
• Sapphire