Sumita Optics (Dongguan)

Optical glass

Optical glass materials, precision-processing preforms, and near-infrared or ultraviolet to visible-light converting glass.

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Functional glass and optical material samples from Sumita

Sumita Optics (Dongguan)

Optical glass material

Optical glass is classified by its nd (refractive index) and vd (Abbe number), which generally falls into two categories: crown glass (with a vd value of over 50) and flint glass (with a vd value of under 50). The crown glass is further divided into series such as BK, K and SK, while the flint glass includes types like F, LF and SF.

The properties of glass material blanks are directly correlated with those of compression-molded products. For low-melting-point optical glass materials used in compression molding, glasses with a high softening point require a high molding temperature, which leads to intense reaction with the mold and thus a drastically shortened mold service life.

Therefore, from the perspectives of mold life extension and production efficiency, mold material selection and mold service life are the most critical issues for low-temperature compression moldability.

Sumita Optics (Dongguan)

Dropped-ball preform

Dropped Sphere Preform refers to a spherical preform lens formed by direct drop molding from molten glass. It features short lead times, low production costs, and rapid response to mass production demands.

※This product is not packaged in a dust-free environment and must be cleaned before use.

Near-spherical falling droplet

Products with a diameter of φ1~3 mm (inclusive) are spherical dropped sphere preforms.

Can correspond to the grades of the materials: K-VC89/80/79/78、K-PSK100/200/300、K-PSFn3、K-CSK120、K-SKLD120/200、K-PG375

Corresponding specifications and detailed parameters
Diameter mm	Diameter tolerance	Roundness	Volume (mm³)
Φ1.0~1.5	±0.020	<0.030	0.524~1.767
Φ1.5~2.0	±0.020	<0.040	1.767~4.189
Φ2.0~2.3	±0.030	<0.050	4.19~6.37
Φ2.3~2.5	±0.030	<0.060	6.37~8.18
Φ2.5~3.0	±0.040	<0.080	8.18~14.14

Falling sphere

Droplet ball products with a diameter of φ3mm or larger are elliptical in shape.

※All the grades listed above are commonly used. Please contact us directly if you need other grades.

Corresponding specifications and detailed parameters
Grade	Specification (mg)	Nitrate Type	Specification (mg)
K-VC78	50~1,700	K-PBK50	100~750
K-VC79	50~3,000	K-PSFn3	60~500
K-VC80	60~3,000	K-PG375	50~220
K-VC89	70~3,000	K-CD45	50~750
K-PSK100	50~1,000	K-SKLD120	50~3,000
K-PSK200	50~400	K-SKLD200	50~3,000
K-PSK300	70~600	K-PBK60	500~3,000
K-CSK120	50~5,000

※If you need information on other grades, please contact us directly.

Grinding ball / bar / sheet / shaped blank

Sumita Optics (Dongguan)

YAGLASS-T NIR-to-visible converting glass

YAGLASS-T detects/converts near-infrared (NIR) light, such as YAG laser beam, to visible light. YAGLASS-T is high transparent glass which contains nano-sized crystals. High threshold against high-power YAG lasers. Compared to previous version ("YAGLASS"), YAGLASS-T is lightweight, more resistant to breakage and chipping. Dimensions of a standard (non-customized) product are 20 x 20 x 2.5 mm. Custom dimensions are available upon request. Same emission intensity (0.55 μm) as the previous version, YAGLASS.

Transmission spectrum (2.5 mm thickness)

Specifications and Basic Properties
Property	Value
Dimensions of detection glass (standard products)	20×20×2.5mm
Detectable range of wavelength	0.9~1.07μm
Detecting sensitivity (when laser at 1.06 μm is used)	30 mW/mm²
Emission wavelength	0.55μm, 0.66μm
Surface damage threshold (laser irradiation at wavelength of 1.06 μm and pulse width of 10 ns)	51 J/cm²
Refractive index (nd)	1.539
Transformation point (Tg)	584°C
Thermal expansion (100–300°C)	89×10⁻⁷/°C
Specific gravity (S.g)	3.4

*Never look at laser beam directly or through lens. Diffused reflected beam is also harmful. *Wear laser protective goggles for operator's eyes. The goggles should be used against scattered beam, so avoid direct beam or reflection beam. *The detection part is made of glass. Please handle with care.

Sumita Optics (Dongguan)

LUMILASS UV-to-visible fluorescent glass

1.Converts a faint UV source of 200–400 nm light into visible light with high efficiency; 2.High sensitivity that allows for visible light detection since a large amount of luminous ions are contained; 3.Minimum sensitivity of ~1 μW/cm² for all emissions; 4.High transparency, homogeneity; 5.Superior durability and water resistance; 6.Keeps high performance after long-hours irradiation with UV light; 7.Excellent machinability, so it can be processed in various forms;

Lumilass-R7 / G9 / B: Fluorescent spectrum, Excitation spectrum, Transmittance

Optical Properties
Property	Lumilass-R7	Lumilass-G9	Lumilass-B
Peak emission wavelength (nm)	610	540	405
Excitation wavelength range (nm)	200~420	140~390	140~400
Min. excitation sensitivity (μW/cm²)	~1	~1	~1
Refractive index (nd)	1.644	1.694	1.477

Thermal and Mechanical Properties
Property	Lumilass-R7	Lumilass-G9	Lumilass-B
Transformation point Tg (°C)	594	660	398
Thermal expansion (α×10⁻⁷)	86	73	176
Specific gravity (S.g)	3.77	3.76	3.65
Vickers hardness (Hv)	633	765	344
Young's modulus E (×10⁸N/m²)	900	1140	650
Modulus of rigidity G (×10⁸N/m²)	340	440	250