Innovations (by field)
Innovations (by product type)
For the world's first we have succeeded in establishing a mass production process for fabricating a nanostructure on a fused silica substrate. This has enabled us to commercialize an inorganic coatingless AR device "i-ARD (inorganic-anti reflection device)" that has an excellent durability and reliability.
|Product name||Coatingless Anti-reflection Device (i-ARD)|
|Dimensions for STD sample||Clear aperture :φ12mm(Outer dimension of holder :φ30mm)|
|Price for STD sample||JPY 100,000(For reference only, consumption tax not included)|
|Release date||Apr. 12, 2010|
|Production volume||1,000 pcs/year|
In recent years, a moth-eye patterned film is known as a new anti-reflection technique. However, this polymer-based product is not durable enough for high power light applications such as laser machining.
As a light source in laser machining equipment, YAG laser is widely employed with modulated wavelength by harmony generation technique: fundamental wave(1064nm,) SHG of 532nm, THG of 355nmand FHG of 266nm.
In order to solve these problems we have developed a technique of fabricating nanostructure designed for AR function on substrate without giving any AR coating. As a consequence of the achievement we have succeeded in mass-manufacturing optical AR device which combines an excellent light resistance for high power and a broadband character at once.
|Dimension||Aperture size 12mm square for standard sample
(Aperture size can be customized upon request.)
|透過率||T>97% (266 ~ 340nm) and T>98% (340 ~ 1200nm) for non polarized light
T>98% (266 ~ 1200nm) for TM light*
|Reflectance||R<2%(266~340nm) and R<1%(340~1200nm)|
|Note||Transmittance property can be customized upon request.|
* When the polarization direction of linearly-polarized light is orthogonal to the optical axis of the device
Until now optical multilayer coating (i.e. use of light interference) has been the most popular technique for adding anti-reflectivity to optical element. But our new product named "i-ARD (inorganic coatingless Anti-Reflection Device)" is of different concept of anti-reflection device. The i-ARD is not given any AR coating but fine nanostructure on its substrate (fused silica) surface for adding anti-reflectivity. This concept has brought great advantages. First, excellent high transmittance and low reflectivity for wide wavelength range have become available at one device.
Specifically, unlike the conventional coating film, there is no film interface, because a nanostructure is directly fabricated on the fused silica substrate. Due to its coatingless this technique completely avoids coating layer-derived problems: heat generation by absorbing light energy, deterioration of optical characteristics or weakening of layer adhesion etc. As a consequence new AR device has given excellent light resistance and durability.
The device is strong enough to be utilized in high power laser equipment, such as laser cutting machine.
|Condition of a light resistance test|
|Type of Laser||Mixed wave (355nm,532nm,1064nm) irradiation|
(Laser wavelength: λ=355nm)
|(1)Power : 250mJ|
|(2)Type : Pulse laser irradiation|
|(3)Beam diameter : φ9mm|
|(4)Frequency : 70Hz (Pulse width : 7~8nsec)|
|i-ARD||No deterioration was shown with more than 50 million pulses irradiated|
|Conventional AR coating||Performance degrade and damages on layer were shown|
More than 100 times as durable as conventional AR coating
How the anti-reflection Window works
By sealing wavelength conversion elements to prevent crystal from deteriorating due to dust or deliquescence, and by making the ant-reflection effect broadband, optical feedback from the window, as well as degradation of the wavelength conversion elements, can be prevented.
(This is particularly a high-value added characteristic for THG or a higher harmonic that requires broad band.)