Light source apparatus and optical communication apparatus using the same

• US 20050122720A1
• Filed: 11/17/2004
• Published: 06/09/2005
• Est. Priority Date: 11/18/2003
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Hiramatsu, Takuma, Shimonaka, Atsushi
• Application Number:
  US10/989,438
• Publication Number:
  US 20050122720A1
• Time in Patent Office: Days
• US Class Current: 362/257
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

A light source apparatus is provided with a light scattering region 5 containing light scattering particles 6 disposed in a part of a region extending from a semiconductor light-emitting laser chip 1 to an external space. An asymmetry factor g of the light scattering particles 6 and a transport optical depth <n> of the light scattering region 5 are set so that their product g.<n> satisfies a following condition:
2≦g·<n>≦40 The light source apparatus is of small-size and low-cost and can ensure safety of human eyes as well as obtain a high optical output.

Claims

1. A light source apparatus, comprising a light scattering region containing light scattering particles disposed in a part of a region extending from a semiconductor light-emitting device to an external space where radiation light radiated from the semiconductor light-emitting device passes, wherein

a product g·

<

n>

of an asymmetry factor g of the light scattering particles and a transport optical depth <

n>

of the light scattering region satisfies a following condition;

2≦

g·

<

n>

≦

40

2. The light source apparatus as defined in claim 1, wherein a product g·

<

n>

of an asymmetry factor g of the light scattering particles and the transport optical depth <

n>

of the light scattering region satisfies a following condition;

2≦

g·

<

n>

≦

15

3. The light source apparatus as defined in claim 1, wherein when an albedo γ

of the light scattering particles is 0<

γ

<

1, the asymmetry factor g of the light scattering particles satisfies a following condition;

$g\le <br><br>0.342<br><br>\text{\hspace{1em}<br><br>}<br><br>{\left(\frac{1}{\mathrm{\gamma <br><br>}}-1\right)}^{-0.116}$

4. The light source apparatus as defined in claim 1,

wherein

when an albedo γ

of the light scattering particles is 0<

γ

<

1, a product g·

<

n>

of the asymmetry factor g of the light scattering particles and the transport optical depth <

n>

of the light scattering region satisfies a following condition;

$2\le <br><br>g·<br><br>\langle <br><br>n\rangle <br><br>\le <br><br>0.146<br><br>\text{\hspace{1em}<br><br>}<br><br>{\left(\frac{1}{\mathrm{\gamma <br><br>}}-1\right)}^{-0.487}$

5. The light source apparatus as defined in claim 1, wherein

when an albedo γ

of the light scattering particles is 0<

γ

<

1, a product g·

<

n>

of the asymmetry factor g of the light scattering particles and the transport optical depth <

n>

of the light scattering region satisfies a following condition;

$2\le <br><br>g·<br><br>\langle <br><br>n\rangle <br><br>\le <br><br>0.110<br><br>\text{\hspace{1em}<br><br>}<br><br>{\left(\frac{1}{\mathrm{\gamma <br><br>}}-1\right)}^{-0.487}$

6. The light source apparatus as defined in claim 1, wherein

the transport optical depth <

n>

of the light scattering region satisfies a following condition;

3≦

<

n>

≦

20

7. The light source apparatus as defined in claim 1, wherein

the asymmetry factor g of the light scattering particles satisfies a following condition:

g<

0.9

8. An optical communication apparatus using the light source apparatus as defined in claim 1.

14. The light source apparatus as defined in claim 1, wherein

the asymmetry factor g of the light scattering particles is obtained from a following formula:

$g={\int <br><br>}_0^{\mathrm{\infty <br><br>}}<br><br>p<br><br>\left(r\right)<br><br>\text{\hspace{1em}<br><br>}<br><br>g_i<br><br>\left(r\right)<br><br>\text{\hspace{1em}<br><br>}<br><br>d<br><br>r,$

wherein p(r) represents particle size distribution probability of the light scattering particles and g_i(r) represents the asymmetry factor when the particle size of the light scattering particles is r.

15. The light source apparatus as defined in claim 1, wherein

the light scattering region is composed of a plurality of light scattering particles, and

the asymmetry factor g of the light scattering particles is obtained from following formulas:

$\begin{array}{c}g=\underset{j=1}{\overset{n}{\sum <br><br>}}<br><br>f_i<br><br>\text{\hspace{1em}<br><br>}<br><br>{\int <br><br>}_0^{\mathrm{\infty <br><br>}}<br><br>p_j<br><br>\left(r\right)<br><br>\text{\hspace{1em}<br><br>}<br><br>g_{\mathrm{ji}}<br><br>\left(r\right)<br><br>\text{\hspace{1em}<br><br>}<br><br>d<br><br>r;<br><br>\mathrm{and}\\ \underset{j=1}{\overset{n}{\sum <br><br>}}<br><br>f_i=1,\end{array}$

wherein f_j(j=1, . . . , n (n is an integer equal to or larger than

     2)) represents a ratio of number of the light scattering particles, p_j(r) represents particle size distribution probability per light scattering particle, and g_ji(r) represents an asymmetry factor when the particle size of the light scattering particles is r.

9. A light source apparatus comprising:

a semiconductor light-emitting device;

a light scattering region containing light scattering particles in a part of a region extending from the semiconductor light-emitting device to an external space where radiation light radiated from the semiconductor light-emitting device passes; and

a reservoir section capable of storing a light scattering material which forms the light scattering region.

10. A light source apparatus, comprising a light scattering region containing light scattering particles disposed in a part of a region extending from a semiconductor light-emitting device to an external space where radiation light radiated from the semiconductor light-emitting device passes, wherein

the light scattering particles contain particles whose diameter is not less than 0.67 times and not more than 1.0 times as large as a central wavelength of the radiation light.

11. The light source apparatus as defined in claim 10, wherein

a difference in refractive index between the light scattering particles and a base material forming the light scattering region is not less than 0.025 and not more than 0.043 times as large as the refractive index of the base material, and a ratio of volumes of mixing of the scattering particles to the base material is not less than 25%.

12. The light source apparatus as defined in claim 10, wherein

a difference in refractive index between the light scattering particles and a base material forming the light scattering region is not less than 0.043 times as large as the refractive index of the base material, and a ratio of volumes of mixing of the scattering particles to the base material is less than 25%.

13. The light source apparatus as defined in claim 10, wherein

the light scattering particles are made of any one of polymethyl styrene, polymethyl methacrylate and polybutyl methacrylate.