An interest of chalcogenide glass has been increased because of their use in preparing optical lenses in range of 3-12 μm.
With recent advance in less costly uncooled detector technology, moldable lens using chalcogenide glass has drawn a
great deal of attention. In this study, amorphous Ge-Sb-Se chalcogenide was prepared by a standard melt-quenching
technique. Melted chalcogenide glass for moldable lens should have unique thermal and mechanic properties in order to
be applied to molding process. Specifically, the Ge:Sb ratio were controlled in order to find out the most stable glass
forming area. Thus, the optical, thermal and thermomechanical properties to find out the specific composition were
characterized by FT-IR spectroscopy, Differential Scanning Calorimeter and Thermo Mechanical Analysis, respectively.
The moldability of chalcogenide glass was characterized through the surface condition of glass samples. Finally, the
preferential Ge:Sb ratio in Ge-Sb-Se based chalcogenide glass system was selected to fabricate moldable lenses.
Although the development of small formats (640x480 pixel arrays) and amorphous silicon microbolometers has greatly
decreased detector cost, another important component of a thermal camera, optics, still prohibit a breakthrough for highvolume
commercial systems. Aspheric lenses used in the thermal imaging are typically made using the costly single
point diamond turning(SPDT) process of expensive single crystal materials (Ge and ZnS, etc). As a potential solution to
reduce cost, compression molding method using chalcogenide glass has been attracted to fabricate IR optic. The present
paper reports fabrication of a molded chalcogenide glass lens module for thermal security camera. In addition, the
molded chalcogenide glass lens was evaluated through form error, roughness and decentration for each surface of the
molded lens. From evaluation results, we verified that the molded lens is capable of adopting to thermal imaging
In this study, we proposed and fabricated optical sensor module integrated onto optical-electrical printed circuit board (PCB) for gas detection based on polymer waveguide with tin oxide thin film. Their potential application as gas sensors are confirmed through computational simulation using the two dimensional finite-difference time-domain method (2DFDTD). Optical-electrical PCB was integrated into vertical cavity surface emitting laser (VCSEL), photodiode and polymeric sensing device was fabricated by the nano-imprint lithography technique. SnO2 thin film of 100nm thickness was placed on the surface of core layer exposed by removing the specific area of the upper cladding layer of 300 μm length and 50 μm width. The performance of the device was measured experimentally. Initial study on the sensor performance for carbon monoxide gas detection indicated good sensitivity.
Chalcogenide glasses have been attracted because of their use in moldable lenses for the application in range of 3-12 μm.
In this study, amorphous Ge-Sb-Se chalcogenide was prepared by a standard melt-quenching technique for moldable lens.
Moldable lens should have unique thermal mechanic properties in order to be applied to molding process. Thus, the
optical and thermal properties to find out right composition were characterized by IR transmission spectroscopy and
DSC, respectively. Specifically, the Ge:Sb ratio were controlled in order to find out the most stable glass forming area.
The relations between thermal properties and the moldability were studied by using an optical microscopy in term of
thermal properties such as Tg and Tx. Transcription properties of the surface of lens or molds were explained in terms of
thermal properties in their composition The preferential Ge:Sb ratio in Ge-Sb-Se based chalcogenide glasses was
selected for producing moldable lens.
With the recent development of less costly uncooled detectors technology, expensive optics are among the remaining
significant cost drivers. As a potential solution to this problem, the fabrication of IR lenses using chalcogenide glasses
has been studied in recent years. We report on fabrication of molded chalcogenide-glass lens for car night-vision and on
the evaluation of the lens. The moldability of chalcogenide glass was characterized through transcription properties of
the mold’s surface. In addition, both IR transmittance and XRD patterns of the molded chalcogenide glass lens were
evaluated to verify the compositional and structural stability of the glass material at the corresponding molding condition.
This paper deals with a new grinding method which adopts a toothed geometry on the grinding wheel for decreasing the
hydrodynamic pressure on grinding arc thereby improving surface roughness of a ground surface. Usually, during the
grinding process, the fluid generates hydrodynamic pressure which increases grinding resistance which is larger than the
net grinding force in extremely small cutting depth. Furthermore, this hydrodynamic pressure worsens wheel rotational
balance which affects ground surface topography. Therefore in this paper, new wheel geometry, specifically tooth shape,
is proposed on the point of decreasing hydrodynamic pressure effect. Experimental data indicates that the proposed
wheel geometry is effective not only on decreasing the hydrodynamic pressure but also improving surface roughness.