1. Field of Invention
The present invention relates to a metallic photonic box and its manufacturing processes, and more particularly to a metallic photonic box that improves the illumination efficiency of light radiation at a certain range of wavelength.
2. Description of Related Arts
Since 1879 when Thomas Edison invented the incandescent light, many efforts have been directed to its improvement of illumination efficiency, energy saving and cost of manufacturing. Given that more than 30 percent of electric power generated worldwide is used in lighting, an illumination apparatus having better illumination efficiency and saving more energy is much needed. This is particularly true when natural resources for generating electricity are exhausting rapidly in today's age.
An incandescent light, as one of the most frequently used illumination apparatuses, includes a tungsten filament having electric current running therethrough for heating to about 2,200 degrees Celsius, thereby generating light radiation. However, it has the shortcomings, such as fragile, less efficient, energy wasting and short living.
Due to the development of technology, fluorescent lights and light emitting diodes (LED) have been invented for better light sources.
Fluorescent Light
A fluorescent light is composed of an air-tight gas discharge tube with its two ends respectively attached with filaments coated with radiator, such as potassium oxide and calcium oxide, for discharging electrons. The gas discharge tube contains argon, neon and krypton added with mercury, having its inner surface coated with fluorescent compositions. When a sufficient voltage is applied to the two ends of the tube, the filaments emit electrons colliding with mercury atoms at a gas discharging state to release ultraviolet rays having a wavelength of 253.7 nm. The ultraviolet rays excite the coated fluorescent composition to generate visible light, whose wavelength depends on its exact composition. Thus, visible light of various colors may be produced by various fluorescent compositions, including yttrium oxide blended with europium, phosphoric lanthanum terbium blended with cerium, and barium, aluminum magnesium oxide blended europium. It is estimated that 60 percent energy of inputting electricity is converted into ultraviolet rays, and only 40 percent energy of the ultraviolet rays is converted into visible light, wherein the rest of the energy is wasted in the form of heat. In other words, the illumination efficiency of fluorescent light is about 24 percent, about twice the efficiency of incandescent light. Although the fluorescent light is energy saving, it is fragile and contains polluting waste.
LED
An LED has many advantages over the traditional incandescent light, including compact, less hot, less energy consuming, longer living and less delaying. However the LED is very selective in terms of material choosing and crystal growth, so the manufacture is difficult. In addition, the voltage required for LED is different from the usual incandescent light and fluorescent light, so additional voltage conversion and AC to DC vonversion is reauired, increasing the cost of LED utilization for illumination purpose. Even so, in order to save energy and protect environment, many developed countries have adopted the LED as the standard lighting device for the twenty first century. Because many countries' energy supply relies on import, there is a great market potential for LED lights. According to estimation, if Japan replaces all its incandescent lights with LED lights, it will save energy consumption for the approximate amount generated by two power plants, which will indirectly reduce the consumption of fuel by one billion liters. As a result, the carbon dioxide released in the course of power generating will also be reduced, thereby alleviating the greenhouse effect.
The issue of building a nuclear power plant has invited heated arguments in Taiwan, and raises the need of discovering new energy and improving energy-using efficiency. If one fourth of the illumination apparatuses can save about thirty percent of energy in Taiwan, 11-billions-kilowatt-per-hour power will be saved, which is about a nuclear power plant's annual capability of power generating. As a result, the carbon dioxide released and fuel consumed for power generation will be reduced accordingly.
Thus, what is needed is an illumination apparatus that can improve the illumination efficiency of the traditional illumination devices in order to save energy without additional efforts for voltage conversion and AC to DC vonversion.
An objective of the present invention is to provide a metallic photonic box and its fabricating techniques, wherein the metallic photonic box defines a cut-off wavelength inhibiting light radiation having a wavelength greater than the cut-off wavelength from resonance.
Another objective of the present invention is to provide a metallic photonic box that is able to transform energy that would have been used for generation of light but for inhibition by the cut-off wavelength, so as to intensify the light radiation at a predetermined wavelength range.
The present invention discloses a metallic photonic box capable of intensifying light at a certain wavelength, comprising: a metallic surrounding forming a resonance chamber; and an insulator layer, disposed in the resonance chamber, having a predetermined dimension defining a cut-off wavelength, which inhibits light of a wavelength greater than the cut-off wavelength from resonating, whereby when the metallic photonic box is heated to generate light radiation, the light radiation is intensified at a wavelength rage predetermined by the cut-off wavelength.
The present invention further discloses a method of making a metallic photonic box for generating light intensified at a certain wavelength, comprising the following steps:
These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
The present invention discloses a metallic photonic box capable of intensifying a electromagnetic radiation at the wavelength range of visible light, wherein the metallic photonic box comprises:
Referring to
The disclosed metallic photonic box defining a resonance chamber alters the behavior of black body radiation. The resonance chamber restrains the electromagnetic field in a metallic surrounding to generate a stationary wave by resonance, which is regulated according to the cut-off wavelength defined by the resonance chamber. According to electromagnetic theories, assuming the metallic photonic box is a cube, its wavelength is defined as:
For example, assuming the refraction rate of the insulator n is 1.5, in order to have a metallic photonic box emitting blue light having a wavelength of 467 nm, the length of the cube a is about 220 nm. If the metallic photonic box is in a shape other than a cube, the same effect can be achieved by calculating the cut-off wavelength according to other electromagnetic theories.
The disclosed metallic photonic box can transfers the energy for certain wavelength to another range of wavelength, so that the light radiation of such range can be intensified. The dimension of the metallic photonic box can be varied for application to areas other than illumination. For example, the metallic photonic box can be used in the area of telecommunication to generate infrared having a wavelength of 1.55 μm. One advantage of the invention is that the metallic photonic box can generate light of various colors simply by varying its dimension. Thus, the metallic photonic box is easier to generate light of various colors than traditional lights.
Accordingly, the metallic photonic box can be formed in any shapes other than a cube, such as a rectangular body, sphere, elliptical body, pyramid and other geometric bodies possibly made by semiconductor manufacturing processes. It is noted that the cubic shape is preferred.
The metallic surrounding of the metallic box is preferred to have a thickness between 1 nm and 10 μm. The metal selected for the metallic photonic box can be any kinds of high fusion temperature, such as tungsten, platinum and gold. The insulator includes, but not limited to, silicon dioxide, silicon nitride, titanium dioxide, air and vacuum.
The disclosed metallic photonic box can be spread on the tungsten filament of incandescent light by semiconductor manufacturing process to increase the illumination efficiency and save energy. Because the traditional incandescent light only converts about five percent energy to visible light, the metallic photonic box improves the illumination efficiency by concentrating most of energy in generating visible light. If the metallic photonic box is widely used in industries and households, the energy saved may amount to the capacity of a nuclear power plant.
The invention discloses a method of making the metallic photonic box, comprising the following steps:
According to step (a), the substrate is made of a material includes, but not limited to, silicon, glass, metal and other thermo-conductive materials. In step (a), the preferable thickness of the metal layer is between 5 nm and 1 μm.
According to step (b), the insulator is formed on the metal layer by means of plasma enhanced chemical vapor deposition (PECVD), chemical vapor deposition, sputtering or spin-on coating.
According to step (c), the photo-resistor layer is formed on the insulator layer by means of photolithography, electron-beam lithography, ion-beam lithography, atomic force lithography or scanning tuning electron lithography.
Accordingly, the metal layer and metal cover are preferably made of materials of high fusion temperature, such as platinum, tungsten and gold.
According to step (g), the thickness of metal cover is between 1 nm and 500 nm.
When a cubic metallic photonic box is wanted, the thickness of the insulator layer should be 50 percent of the desired wavelength, and each square of the photo-resistor layer has a side of 50 percent of the desired wavelength. In step (e) the thickness of the insulator layer is no greater than that of the insulator layer in step (e).
The disclosed metallic photonic box can be coated on a tungsten filament, through which an electric current runs to generate heat for the metallic photonic box to generate black body radiation. The resonance chamber defined in the metallic photonic box improves the illumination efficiency of visible light and saves energy.
Thus, the present invention further discloses a light source comprising:
The disclosed light source is further explained in the following paragraphs:
Referring to
As an alternative shown in
The temperature required for the metallic photonic box to function properly is lower than the traditional lights, because it alters the spectrum of black body radiation and enhances the wavelength of visible light. In other words, in order to achieve the same intensity of visible light, the metallic photonic box requires lower energy than the traditional lights. Moreover, the metallic photonic box is packed in a vacuum environment, whose pressure is far lower than 1 torr, to reduce its oxidation rate.
The color of the light radiated from the metallic photonic box may be varied by adjusting its dimension, according to the following electromagnetic equation:
The present invention has many applications. For example, the metallic photonic boxes of three various dimensions can be made on a substrate that is heated to generate white light, composed of red, green and blue light. The disclosed metallic photonic box is superior to the traditional incandescent lamps in the sense that it increases the illumination efficiency and having the light whiter than the traditional one. The metallic photonic box can also be used in liquid crystal displays as the background light source to reduce the size of the displays.
If the dimension of the metallic photonic box is fixed, the color of light it generates is fixed too. Thus, it could be suitable as traffic lights or signals. Because a traditional traffic light requires a tainted glass to generate light of certain colors, the disclosed metallic photonic box has the advantages of illumination efficiency and simplicity of manufacturing. This is true even comparing with the traffic light made by LEDs.
The disclosed metallic photonic box can be applied to make a display. Each box can be divided into many pixels. By controlling the electric current, the pixel may generate light of various colors. Because the metallic photonic box is smaller than 1 μm, the metallic photonic box can be used to make a high resolution display, which does not require background light source, color filter and liquid crystal materials that are usually needed for an LCD, such that its manufacturing is easier and cost is lower. Due to the elasticity of metal, the metallic photonic box is able to accommodate various contours of displays.
The metallic photonic box can be used to make telecommunication elements. In order to generate electromagnetic radiation having a wavelength of 1.55 μm that is generally required by telecommunication elements, the metallic photonic box can be made as a cube having a dimension of 730 nm for each side. Likewise, the disclosed metallic photonic box can be made to generate electromagnetic radiation with various wavelengths for applications in other areas.
The following is an example detailing the manufacturing process of the disclosed metallic photonic box:
Referring to
One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.
It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.
Number | Name | Date | Kind |
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20020131695 | Masuda et al. | Sep 2002 | A1 |
Number | Date | Country | |
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20050133926 A1 | Jun 2005 | US |