JP2003258353A - Light source device and light communication system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and inexpensive light source device which is safe for a human eye even if a high output semiconductor light emitting element is used, has high light output efficiency, low power consumption, and is suitable for a light communication system having a high speed and wide communication area and to provide the light communication system. <P>SOLUTION: A region 120 including a dynamic light scattering system formed by liquid including a light scattering body is arranged in the optical path of emitted light from a semiconductor laser 100. Liquid including the light scattering body is silicone oil including at least one light scattering body among particulate formed of organic particulate and silicon oxide and particulate formed of titanium oxide. The product of viscosity of liquid including the light scattering body and the particle size of the light scattering body is almost 1.5×10<SP>-1</SP>Pa.s.μm or not more than 1.5×10<SP>-1</SP>Pa.s.μm, and a normalization displacement Δ1/λ of the light scattering body is almost 1/100 or not less than 1/100. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device in which a semiconductor light emitting element is mounted on a structure such as a resin substrate, a lead frame or a small stem, and an optical communication system using the light source device. The present invention relates to a light source device ensuring eye safety and an optical communication system using the same.

[0002]

2. Description of the Related Art In recent years, the infrared communication module conforming to the IrDA (Infrared Data Association) standard has been rapidly miniaturized and has a short distance.
(20 cm) The diameter and height of the lens part of the specification product is 1 mm to 2
It has reached about mm. Regarding communication speed, while IrDA is gradually increasing in speed, optical wireless LAN products have a base station that earns light quantity by arranging 20 or more shell-shaped LEDs in parallel, and a sharp directivity and tracking function. Communication distance of several meters and 1
Compatibility of high speed up to about 00 Mbps is being sought.

In such a wireless optical communication technique, there are situations where directivity and shielding are problems, but by taking advantage of high speed and confidentiality, especially cost advantage, palmtop or handheld type portable terminals. It is expected that its application will be developed as a high-speed interface for equipment. However, the above-mentioned high-speed optical wireless LAN (local area network) products are generally large in size and consume considerable power. In the past, there have been many attempts to use a relatively inexpensive semiconductor laser in the near-infrared wavelength region as an eye-safe for wireless optical communication, with an emphasis on speeding up.
Many use relatively large-scale diffuser plates and beam shaping optical systems, and it has been difficult to realize downsizing and price reduction comparable to IrDA-compliant products.

That is, existing IrDA and optical wireless LAN
The small and inexpensive transceiver module required to fill the gap between the two and realize a wireless optical communication system having a higher speed and a wider communication area has never been put into practical use.

Further, recently, the present applicant has proposed a light source device capable of ensuring the safety of human eyes even when a high-power semiconductor laser is used as a light source element, and a wireless optical communication system having a high speed and a wide communication area. A suitable small light source device was manufactured. Note that this light source device is described in order to facilitate understanding of the present invention, and is not a publicly known technique and is not a conventional technique.

As shown in FIG. 15, the light source device has a resin substrate 1203 having a recess 1204, a semiconductor laser 1200 arranged in the recess 1204, and a protrusion provided so as to cover the recess 1204. Point 1
209 and an epoxy resin mold part 1205. The region within the recess 1204 contains the light scatterer in high concentration and uniformly. A wiring pattern 1207 is formed on the resin substrate 1203 and in the recess 1204, and the lower electrode of the semiconductor laser 1200 is connected to the wiring pattern 1207 in the recess 1204 while the upper electrode of the semiconductor laser 1200 is The electrode 1208 provided on the resin substrate 1203 is connected via a wire 1202. The highly coherent light emitted from the semiconductor laser 1200 is diffused by multiple scattering in the region including the light scatterer of the recess 1204, and travels in the direction of the optical axis 1201. In the region including the light scatterer of the recess 1204,
A gel-like or rubber-like substance is injected and cured by heat or light.

The light emitted from the semiconductor laser 1200 passes through a region containing the light-scattering body filled with a gel-like or rubber-like substance and passes through the epoxy resin mold portion 120.
Pass 5. When the light scatterers are highly concentrated and uniformly dispersed in the region containing the light scatterer filled with a gel-like or rubber-like substance, the high-contrast speckle generated in the near-field image is suppressed to some extent. be able to.

Here, as an index for estimating the speckle amount of the near-field image, the standard deviation σ of the ratio (Peak-to-Average Ratio) of the light intensity at the position of the near-field image is used. In the region containing the light scatterer filled with a gel-like or rubber-like substance, static light multiple scattering is caused, but since the aggregated light scatterers remain difficult to settle, the PAR standard deviation σ of the near-field image is The value can be reduced only to about 0.1, and it is not easy to suppress the speckle to a level σ = 0.08, which is a safe eye for human eyes. When using a gel in the region containing the light scatterer,
Although it is conceivable to increase the density in order to further reduce the value of the PAR standard deviation σ of the near-field image, there is a problem that the light extraction efficiency is extremely deteriorated and it cannot be put to practical use. If the kneading state is good and the aggregation of light scatterers can be reduced, PA
The R standard deviation σ can be further reduced.

Therefore, an object of the present invention is to obtain a high light extraction efficiency, which is safe for human eyes even with a high-power semiconductor light emitting device with a simple structure, and has low power consumption and a small size and low power consumption. An object of the present invention is to provide a light source device which is cost-effective, suitable for an optical communication system having a high speed and a wide communication area, and an optical communication system using the same.

[0010]

When the stimulated emission light from a semiconductor laser is emitted into a space for optical wireless communication as a semiconductor light emitting element, the most serious problem is that the highly coherent light of the laser light is emitted by the human eyeball. To reach and damage the retina inside. In order to convert such highly coherent light into incoherent light that does not damage humans, the light-scattering material is dispersed in high concentration and uniformly in the gel-like substance or rubber-like substance that seals the semiconductor laser. The way to
Due to static light multiple scattering, speckles at a level that damages the human eye remain in the near-field image. That is,
When the output light from a light source having speckles enters the eyeball through some optical system, the fine structure of the speckles contained in the image formed on the retina causes local concentration of power density, which leads to laser light. May cause idiosyncratic retinal heat damage.

Therefore, in the vicinity of the semiconductor laser, dynamic light multiple scattering can be obtained by using a liquid or swollen gel instead of the gel-like or rubber-like substance that fills the region including the static light-scattering system. Therefore, there is a possibility that the above problems can be solved. The dynamic light multiple scattering referred to here mainly includes Brownian motion, and can significantly increase the light scattering effect as compared with the static light multiple scattering.

Therefore, in order to achieve the above object, the light source device of the present invention is characterized by having a region including a dynamic light scattering system in the optical path of the light emitted from the semiconductor light emitting element.

According to the light source device having the above structure, the emitted light from the semiconductor light emitting element is highly coherent from, for example, a semiconductor laser due to dynamic light multiple scattering when passing through a region including a dynamic light scattering system. By converting light into incoherent light that does not damage humans, local concentration of power density does not occur in the image formed on the retina when it enters the eyeball, and retinal heat damage is prevented. Therefore, with a simple structure, even if a high-power semiconductor light-emitting element is used, it is safe for human eyes and the light extraction efficiency is obtained, and the power consumption is small and the size and cost can be reduced. A light source device suitable for an optical communication system having a wide communication area can be realized. The semiconductor light emitting device is not limited to the semiconductor laser, and the same effect can be obtained even if it is a light emitting diode. In addition, the dynamic light scattering system is a system in which the direction of scattered light is temporally fluctuated by utilizing Brownian motion or the like.

Further, the light source device of one embodiment is characterized in that the semiconductor light emitting element is a semiconductor laser.

According to the light source device of the above embodiment, by using the semiconductor laser for the semiconductor light emitting element, a light source device suitable for high speed communication with high output and low power consumption can be obtained. Particularly, in a semiconductor laser that emits highly coherent light, the highly coherent light is effectively converted into incoherent light that does not damage humans, so that a light source device that is safe for human eyes can be provided.

The light source device of one embodiment is characterized in that the region including the dynamic light scattering system is formed of a liquid containing a light scatterer.

According to the light source device of the above embodiment, in the liquid including the light scatterer forming the region including the dynamic light scattering system, the direction of the scattered light of the incident light is changed in the liquid. It can be fluctuated in time by using the Brownian motion of.

In the light source device of one embodiment, the liquid containing the light scatterer contains at least one light scatterer of organic fine particles, fine particles of silicon oxide, and fine particles of titanium oxide. It is characterized by being silicone oil.

According to the light source device of the above embodiment, the liquid containing the light scatterer contains at least one light scatterer of organic fine particles, fine particles of silicon oxide, and fine particles of titanium oxide. The use of silicone oil makes it possible to obtain a dynamic light scattering system in which the direction of scattered light is temporally varied by utilizing Brownian motion or the like.

In the light source device of one embodiment, the product of the viscosity (Pa.s) of the liquid containing the light scatterer and the particle size (μm) of the dispersed light scatterer is about 1.5 ×. It is characterized in that it is 10 ⁻¹ Pa · s · μm or 1.5 × 10 ⁻¹ Pa · s · μm or less.

According to the light source device of the above embodiment, the viscosity (Pa.s) of the liquid containing the light scatterer and the particle size of the light scatterer are determined.
The product of (μm) is approximately 1.5 × 10 ⁻¹ Pa · s · μm or 1.
By using a liquid containing a light scatterer that satisfies the condition of 5 × 10 ⁻¹ Pa · s · μm or less, the structure of the speckle pattern is made finer to the level of the movement of the eyeball in the fixation state, and the disturbance amplitude is reduced. Reduces the temporal and spatial coherence until can no longer be observed,
The light intensity of the near-field image can be made eye-safe, and an eye-safe light source device can be realized.

Further, the light source device of one embodiment is characterized in that the region including the dynamic light scattering system is formed of swollen gel including a light scatterer.

According to the light source device of the above embodiment, in the swollen gel containing the light scatterer forming the region including the dynamic light scattering system, the direction of scattered light of incident light is in the swollen gel. It can be temporally fluctuated by utilizing the Brownian motion of the light scatterer. The swollen gel containing the light scatterer is a gel that has increased volume by absorbing a liquid,
There is a light scatterer in the liquid absorbed by the gel.

In the light source device of one embodiment, the swollen gel containing the light-scattering body is a silicone gel swollen by absorbing silicone oil, and the fine particles are made of organic fine particles and silicon oxide, and titanium. It is characterized in that it is the above-mentioned silicone gel containing at least one light-scattering body among the fine particles made of an oxide.

According to the light source device of the above embodiment, as the swollen gel containing the light scatterer, the silicone gel that has swollen by absorbing silicone oil is composed of organic fine particles such as acrylic and fine particles of silicon oxide. A dynamic light scattering system in which the direction of scattered light is temporally fluctuated by utilizing Brownian motion or the like can be obtained by using a material containing at least one light scatterer of fine particles and titanium oxide.

Further, in the light source device of one embodiment, the product of the viscosity (Pa · s) of the swollen gel containing the light scatterer and the particle size (μm) of the dispersed light scatterer is approximately 1. 5 × 10 ^-1 Pa · s ・
or less than 1.5 × 10 ⁻¹ Pa · s · μm.

According to the light source device of the above embodiment, the product of the viscosity (Pa · s) of the swollen gel containing the light scatterer and the particle size (μm) of the light scatterer is about 1.5 × 10 ^−. By using a swollen gel that satisfies the condition of ¹ Pa · s · μm or 1.5 × 10 ⁻¹ Pa · s · μm or less, the structure of the speckle pattern can be achieved up to the movement of the eyeball in the fixation state. It reduces the coherence in time and space until it becomes finer and the disturbance amplitude cannot be clearly observed.
The light intensity of the near-field image can be made eye-safe, and an eye-safe light source device can be realized.

Further, in the light source device of one embodiment, in the light scatterer dispersed in the region including the dynamic light scatterer, the oscillation wavelength of the semiconductor laser is set to λ, and the light scatterer 3 is used.
When the displacement amount indicating the spread in the time of 0 ms is Δl, the normalized displacement amount Δl / λ of the light scatterer at the oscillation wavelength of 30 ms is about 1/100 or 1
/ 100 or more.

Here, the displacement amount Δl representing the spread of the light scatterer in a time period of 30 ms represents the extent to which the light scatterer spreads from one point in the solvent over time, and the displacement amount Δl is The smaller the spread, the smaller the spread, and the larger the displacement Δl, the larger the spread. According to the light source device of the above-mentioned embodiment, regarding the light scatterer dispersed in the region including the dynamic light scattering system, when the oscillation wavelength of the semiconductor laser is λ, 3 of the light scatterers necessary for eye-safe.
Normalized displacement Δl at oscillation wavelength λ in 0 ms time
/ Λ is required to be about 1/100 or more. More preferably, it is 2/100. Here, 30 ms means
It is the time for one frame of the CCD used for observation, and is almost the same length as the cycle of the fastest movement of human microscopic eye movements.

Further, the light source device of one embodiment has a mold region made of epoxy resin that covers the region including the dynamic light scattering system, and at least a part of the wire directly or indirectly connected to the semiconductor light emitting device. Is in the mold region.

If the mold region made of the epoxy resin or the region containing the dynamic light scattering system is damaged for some reason, eye safety may not be realized. Therefore, according to the light source device of the above-described embodiment, at least a part of the wire directly or indirectly connected to the semiconductor light-emitting element exists in the mold region made of epoxy resin that covers the region including the dynamic light-scattering system. By doing so, when the mold region or the region including the dynamic light scattering system is damaged, the wire passing through the mold region is cut, so that the light emitted from the semiconductor light emitting element is blocked and the eye safe is maintained. be able to.

The optical communication system of the present invention is characterized in that any one of the above light source devices is used as a transmitting means.

According to the optical communication system having the above-mentioned structure, by using the above-mentioned light source device as the transmitting means, it is safe for human eyes, and the power consumption is small, the size and cost can be reduced, and the operation speed is high. An optical communication system having a wide communication area can be realized.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION A light source device of the present invention and an optical communication system using the same will be described in detail below with reference to the embodiments shown in the drawings. (First Embodiment) FIG. 1 is a sectional view showing the arrangement of an eye-safe light source device as a light source device according to the first embodiment of the present invention.

In the eye-safe light source device of the first embodiment, as shown in FIG. 1, a resin substrate 103 is provided with a frustoconical recess 104 that spreads upward, and the recess 10 is provided.
A semiconductor laser 100 is arranged in the position 4. An Au-plated wiring pattern 107 is formed on the resin substrate 103 and the recess 104, and a lower electrode (not shown) of the semiconductor laser 100 is electrically connected to the Au-plated wiring pattern 107 of the recess 104. On the other hand, the upper electrode (not shown) of the semiconductor laser 100 is formed on the resin substrate 103 and the recess 104.
It is electrically connected to the electrode 108 provided in the vicinity through the wire 102. Further, a cylindrical portion 109 is arranged on the resin substrate 103 so as to surround the recess 104. The cylindrical portion 109 is connected to the resin substrate 103 or the wiring pattern 10.
It is fixed on the No. 7 by silver paste. Further, by forming a metal layer 110 on the inner wall of the cylindrical portion 109 by Ag plating, the inner surface is made a reflecting surface.

A liquid in which the light scatterer is uniformly dispersed in a desired concentration inside the concave portion 104 and inside the cylindrical portion 109.
(Or swollen gel) to fill the region 120 containing the dynamic light scattering system. Then, the cylindrical portion 109
The upper part is covered with transparent glass 111 to confine the liquid (or swollen gel) in the region 120 including the dynamic light scattering system. As the liquid containing the light scatterer, silicone oil containing at least one light scatterer among organic fine particles such as acrylic particles, fine particles made of silicon oxide, and fine particles made of titanium oxide is used. The swollen gel containing the light-scattering body is a silicone gel swollen by absorbing silicone oil, which is composed of organic fine particles such as acrylic and fine particles made of silicon oxide and fine particles made of titanium oxide. At least one of
A silicone gel containing two light scatterers is used.

Then, a mold portion 105 made of epoxy resin is formed on the resin substrate 103. The mold part 105 has a convex lens shape in a region corresponding to the transparent glass 111 in order to shape the far-field pattern.
The manufacturing process of this mold part 105 is from about 80 ° C. to 15
It can be performed in the range of 0 ° C. A light scatterer may be dispersed in the mold section 105.

In the eye-safe light source device having the above structure,
Highly coherent light from the semiconductor laser 100 is typically emitted from a spot on the order of μm of the semiconductor laser 100, diffused by multiple scattering in the region 120 including the dynamic light scattering system, and generally in the direction of the optical axis 101. Proceed to. Since the multiple scattering region, which is the region 120 including the dynamic light scattering system, is composed of a fluid, the transparent glass 111 is included in the manufacturing process.
As described above, a mechanism for confining a fluid with a transparent material with a minimum transmission loss is required by some method.

FIG. 2 is a diagram showing the results of an experiment conducted by the present applicant, with the viscosity of the fluid as a parameter, and 0.02 Pa ·
In the range from s to 10 Pa · s, the particle size r of the light scatterer (horizontal axis in FIG. 2) and the displacement amount Δl at a time of 30 ms
FIG. 3 is a diagram showing a relationship with a standardized displacement amount Δl / λ (vertical axis in FIG. 2) obtained by normalizing with the oscillation wavelength λ of the semiconductor laser. In addition,
The displacement Δl is

[Equation 1] (However, 1 is a displacement amount, K _B is a constant, T is temperature, t is time, η is viscosity, and a is diameter).

In FIG. 2, among the experimental values, ◯ indicates the case where the PAR standard deviation σ of the near-field image is 0.08 or less, which is eye-safe, and × indicates the PAR standard deviation σ is 0.08, which is not eye-safe. The case is large. Also,
The solid line shown in FIG. 2 indicates the relationship between the particle size r of the light scatterer and the normalized displacement amount Δl / λ, which is obtained using the above relational expression. The dotted line shown in FIG. 2 indicates the boundary of whether the PAR standard deviation σ is around 0.08, that is, whether it is eye-safe. From FIG. 2, in order for the near-field image speckles to reach the eye-safe level, it is desired that the viscosity of the fluid serving as the base material be low and the particle size of the light scatterer be minute. Normalized displacement of light scatterer that almost satisfies eyesafe Δl / λ
Is about 1/100, but more preferably 2/100
Is.

When the relationship between the viscosity and the particle size required for eye-safe is quantified, the viscosity of the liquid (or swollen gel) containing the light scatterer is dispersed from the boundary shown by the dotted line in FIG. The product of the particle size of the light scatterer is about 1.5 ×
By setting it to 10 ⁻¹ Pa · s · μm or less, it can be derived that the speckle of the near-field image becomes the eye-safe level.

On the other hand, when the viscosity of the fluid is about 10 Pa · s,
This can be achieved when the particle diameter of the light scatterer is smaller than 10 nm, and the possibility of realizing the eye-safe level becomes low.

(Second Embodiment) FIG. 3 is a sectional view showing the structure of an eye-safe light source device according to the second embodiment of the present invention.
In this eye-safe light source device, as the liquid containing the light scatterer, silicone oil (viscosity 0.5 Pa · s) is used as the liquid, and fine particles of titanium dioxide having a particle diameter of 15 nm are used as the light scatterer.

This eye-safe light source device has a wiring pattern 30 formed on a resin substrate 303, as shown in FIG.
The submount 308 is fixed on the submount 30
On the electrode 312 formed on the side surface of the semiconductor laser 3
00 is arranged so that the emitting end faces upward in FIG.
The semiconductor laser 300 and the electrode 312 on the submount 308 are electrically connected via a bonded wire 302. The cylindrical portion 3 is formed so as to surround the submount 308 on which the semiconductor laser 300 is mounted.
09 is fixed onto the resin substrate 303 or the wiring pattern 307 by silver paste. A metal layer 310 is formed on the inner wall of the cylindrical portion 309 by Ag plating.

The cylindrical portion 309 is filled with a non-electrolyte liquid containing a light scatterer uniformly dispersed at a desired concentration,
The region 304 including the dynamic light scattering system is formed, and the cylindrical portion 309 is formed.
By covering the upper part with the transparent glass 311, the liquid in the region 304 including the dynamic light scattering system is sealed. The region 304 including the dynamic light scattering system has a wiring pattern 307 on the resin substrate 303 and the metal layer 310 of the cylindrical portion 309, and the inner surface thereof is a reflecting surface except for the upper side. The light emitted from the semiconductor laser 300 travels in the direction of the optical axis 301 and is diffused in the region 304 including the dynamic light scattering system,
Converted to incoherent light.

Note that, in FIG. 3, the mold portion is the same as that of the eye-safe light source device shown in FIG. 1 of the above-described first embodiment, and therefore the illustration and description thereof are omitted.

FIG. 4 shows a near-field image in the eye-safe light source device shown in FIG. For comparison, viscosity 2Pa ・ s
FIG. 5 shows a near-field image when acrylic particles having a diameter of 2 μm are uniformly dispersed in the silicone gel of 3 at a weight concentration of 30%. 4 and 5 show a curve of raw data showing a light intensity distribution of a near-field image, a curve of average intensity distribution obtained from surrounding data based on the curve, and a curve of the average intensity distribution. Three types of curved lines representing the displacement of the raw data are drawn. In addition, in FIG. 4 and FIG. 5, it is difficult to see the curve of the raw data and the curve of the average intensity distribution, which are difficult to see,
The smooth curve is the average intensity distribution. Also, in FIG.
Regions of low relative intensity on both sides of the curve representing the displacement of the raw data from the curve of the average intensity distribution of FIG. 5 are omitted.

In FIG. 4, as compared with FIG. 5, the curve of the raw data and the curve of the average intensity distribution are substantially overlapped with each other, and the fluctuation of the light intensity depending on the position is small. It can be seen that the speckle amount is smaller. Figure 4
The PAR standard deviation σ of the near-field image is 0.06, and the PAR standard deviation σ of the near-field image is 0.1 in FIG. Is obtained.

Even with silicone oil, the viscosity is 5 Pa.
In the case of increasing to s, even if the particle size of the light scatterer is 15 nm, the PAR standard deviation σ of the near-field image is 0.13, and the speckle amount does not reach the eye-safe level.

(Third Embodiment) FIG. 6 is a sectional view showing the structure of an eye-safe light source device according to the third embodiment of the present invention.
This eye-safe light source device uses milk as a solution of an electrolyte as a liquid containing a light scatterer. The viscosity of milk is about 1.5 mPa · s. In the case of an electrolyte, if it comes into direct contact with the semiconductor laser, characteristics such as light emission efficiency may be deteriorated due to a short circuit. Therefore, it is necessary to adopt the configuration as described below. In this case, the fluid used may be a non-electrolyte.

This eye-safe light source device has a wiring pattern 40 formed on a resin substrate 403 as shown in FIG.
7 mount the submount 408 on the
On the electrode 416 formed on the side surface of the semiconductor laser 4
00 is arranged so that the emitting end faces upward in FIG.
The semiconductor laser 400 and the electrode 416 on the submount 408 are electrically connected via a bonded wire 402.

The cylindrical portion 409 is formed on the resin substrate 40 so as to surround the submount 408 on which the semiconductor laser 400 is mounted.
3 or the wiring pattern 407 is fixed by silver paste. A metal layer 410 is formed on the inner wall of the cylindrical portion 409 by Ag plating. The submount 408 on which the semiconductor laser 400 is mounted is a cylinder 409.
It is contained in the space 404 and is sealed by the transparent glass 411.

Further, after covering the upper portion of the cylindrical portion 409 with the transparent glass 411, a cylindrical portion 413 having the same diameter as the cylindrical portion 409 is fixed on the transparent glass 411 by Ag paste. A metal layer 412 is formed on the inner wall of the cylindrical portion 413 by Ag plating.

The cylindrical portion 413 is filled with milk as a non-electrolyte liquid containing a light scatterer to form a region 414 containing a dynamic light scattering system, and the upper portion of the cylindrical portion 413 is made of transparent glass 4.
Covering with 15 seals the liquid in the region 414 containing the dynamic light scattering system. Region 414 containing the dynamic light scattering system
The metal layer 412 of the cylindrical portion 413 makes the inner surface except the upper side a reflecting surface. The light emitted from the semiconductor laser 400 travels in the direction of the optical axis 401, is diffused in the region 414 including the dynamic light scattering system, and is converted into incoherent light.

Note that, in FIG. 6, the mold portion is the same as that of the eye-safe light source device shown in FIG. 1 of the above-mentioned first embodiment, and therefore the illustration and description thereof are omitted.

The PAR standard deviation σ of the near-field image in this system is 0.045, and when milk is used, a value that can withstand eye-safe can be obtained without any problem.

(Fourth Embodiment) Since the base material that fills the region including the dynamic light scattering system is a fluid, means for sealing is required. It is desirable that the material to be sealed be transparent and that the light transmission loss be as small as possible. In the fourth embodiment, a method of sealing a base material that fills a region including a dynamic light scattering system will be described.

FIG. 7 is a sectional view showing the structure of an eye-safe light source device according to the fourth embodiment of the present invention. This eye-safe light source device has a particle size of 15 nm in isopropyl alcohol (IPA) as a liquid containing a light scatterer. A fluid in which titanium dioxide is dispersed is used. The viscosity of this fluid is 25 mP
a · s.

In this eye-safe light source device, as shown in FIG. 7, a circular truncated cone-shaped concave portion 504 is provided on a resin substrate 503, and the semiconductor laser 500 is arranged in the concave portion 504. An Au-plated wiring pattern 507 is formed on the resin substrate 503 and the recess 504,
A lower electrode (not shown) of the semiconductor laser 500 is electrically connected to the Au-plated wiring pattern 507 in the recess 504. On the other hand, the upper electrode (not shown) of the semiconductor laser 500
Is electrically connected to an electrode 508 provided on the resin substrate 503 and in the vicinity of the recess 504 via a wire 502. Further, a cylindrical portion 509 is arranged on the resin substrate 503 and around the recess 504. The cylindrical portion 509 is fixed on the resin substrate 503 or the wiring pattern 507 with silver paste. Further, by forming a metal layer 510 on the inner wall of the cylindrical portion 509 by Ag plating,
The inner surface is a reflective surface.

A liquid in which the light scatterers are uniformly dispersed in a desired concentration inside the recess 504 and inside the cylindrical portion 509.
(Or swollen gel) to fill the region 520 containing the dynamic light scattering system. A region 520 including the dynamic light scattering system, which covers the upper portion of the cylindrical portion 509 with the transparent glass 511.
Entraps the liquid (or swollen gel). The emitted light from the semiconductor laser 500 is diffused by multiple scattering in the region 520 including the dynamic light scattering system, and the optical axis 5 is almost the same.
Go in the direction of 01.

In the fourth embodiment, as a method for filling the multiple light scattering region with a fluid, a large amount of fluid is injected into the region including the dynamic light scattering system and once overflowed,
It is sealed with transparent glass 511. And the overflowing fluid 51
By drying 2 with heat or the like and then solidifying it with a thermosetting (or photocuring) adhesive 513, the fluid can be confined without gas being mixed. Since isopropyl alcohol (IPA) has a very high volatility, it is not always necessary to apply heat or the like for drying.

However, this isopropyl alcohol (I
Due to the high volatility of PA), it is conceivable that concentration by volatilization occurs at the stage of injecting IPA into the region 504 including the dynamic light scattering region. In such a case, the module is completely immersed together with the area 520 including the dynamic light scatterer in a container containing a sufficient amount of IPA in which the light scatterer is dispersed. The transparent glass 511 and the cylindrical portion 509 are sealed in IPA using a pressure-sensitive adhesive material. Then, after pulling up the module from the container, the transparent glass 511 and the cylindrical portion 509 are completely fixed with an adhesive or the like. As described above, even a highly volatile fluid can be sealed.

Note that, in FIG. 7, the mold portion is the same as that of the eye-safe light source device shown in FIG. 1 of the first embodiment, and therefore the illustration and description thereof are omitted.

In the fourth embodiment described above, the PAR standard deviation σ of the near-field image when IPA is used is 0.02, and it can be used as an eye-safe without any problem.

Next, an outline of the manufacturing process of the eye-safe light source device shown in FIG. 7 will be described with reference to FIGS. First, as shown in FIG. 8A, the semiconductor laser 600 is fixed in the recess 604, which is a region including the dynamic light scattering system, and wire bonding 602 is performed. Next, as shown in FIG. 8B, the cylindrical portion 609 having the metal layer 610 formed on the inner peripheral surface by Ag plating is attached to the resin substrate 60.
It is made to adhere on 3 by silver paste etc. Next, as shown in FIG. 8 (c), the region inside the recess 604 and the region inside the cylindrical portion 609 (region including the dynamic light scattering system) is filled with a liquid containing a light scatterer (or swollen gel). The transparent glass 611 is placed on the upper part of the cylindrical portion 609, and the transparent glass 611 is fixed with a thermosetting or photocurable adhesive 613 to seal the liquid containing the light scatterer.

(Fifth Embodiment) FIG. 9 is a sectional view showing the arrangement of an eye-safe light source device according to the fifth embodiment of the present invention.
In the fifth embodiment, a method of sealing a base material that fills a region including a dynamic light scattering system will be described.

As shown in FIG. 9, this eye-safe light source device has a resin substrate 703 provided with a frustoconical recess 704 extending upward, and the semiconductor laser 700 is disposed in the recess 704. An Au-plated wiring pattern 707 is formed on the resin substrate 703 and in the recess 704,
A lower electrode (not shown) of the semiconductor laser 700 is electrically connected to the Au-plated wiring pattern 707 in the recess 704. On the other hand, the upper electrode (not shown) of the semiconductor laser 700
Are electrically connected to an electrode 708 provided on the resin substrate 703 and near the recess 704 via a wire 702. Further, a cylindrical portion 709 is arranged on the resin substrate 703 so as to surround the concave portion 704. The cylindrical portion 709 is fixed on the resin substrate 703 or the wiring pattern 707 with silver paste. Further, a metal layer 710 is formed on the inner wall of the cylindrical portion 709 by Ag plating to make the inner surface a reflecting surface.

A liquid in which the light scatterer is uniformly dispersed in a desired concentration inside the recess 704 and inside the cylindrical portion 709.
(Or swollen gel) to fill the region 720 containing the dynamic light scattering system. The upper part of the cylindrical portion 709 is covered with transparent glass 711, and the transparent glass 711 is fixed with a thermosetting or photocuring substance to confine the liquid (or swollen gel) in the region 720 including the dynamic light scattering system. There is. Light emitted from the semiconductor laser 700 is diffused by multiple scattering in a region 720 including the dynamic light scattering system,
It proceeds in the direction of the optical axis 701.

In the fifth embodiment, as a method for filling the multiple scattering region, which is the region 720 including the dynamic light scattering system, with a fluid, a hole is made in a part of the cylindrical portion 709 and the light is scattered by the thin tube 714. Inject body-containing fluid (non-electrolyte liquid or swollen gel). At this time, a partition may be provided in the thin tube 714 so as to have two passages so that the gas extruded by exchanging the fluid can be easily passed. Then, after the inside of the cylindrical portion 709 is filled with the fluid, the hole for the thin tube 714 is closed with a thermosetting or photocuring substance, thereby completing the filling of the fluid.

Note that, in FIG. 9, the mold portion is the same as that of the eye-safe light source device shown in FIG. 1 of the above-described first embodiment, and therefore the illustration and description thereof are omitted.

(Sixth Embodiment) FIG. 10 is a sectional view showing the arrangement of an eye-safe light source device according to the sixth embodiment of the present invention. In the sixth embodiment, a method of sealing a base material that fills a region including a dynamic light scattering system will be described.

In this eye-safe light source device, as shown in FIG. 10, a resin substrate 803 is provided with a truncated conical recess 804 that expands upward, and the semiconductor laser 800 is disposed in the recess 804. An Au-plated wiring pattern 807 is formed on the resin substrate 803 and the recess 804, and a lower electrode (not shown) of the semiconductor laser 800 is electrically connected to the Au-plated wiring pattern 807 of the recess 804. On the other hand, an upper electrode (not shown) of the semiconductor laser 800 is electrically connected to an electrode 808 provided on the resin substrate 803 and in the vicinity of the recess 804 via a wire 802. Further, a cylindrical portion 809 is arranged on the resin substrate 803 so as to surround the concave portion 804. The cylindrical portion 80
9 on the resin substrate 803 or wiring pattern 807.
It is fixed by paste. Further, the cylindrical portion 8
By forming a metal layer 810 on the inner wall of 09 by Ag plating, the inner surface is made a reflective surface.

A liquid in which the light scatterers are uniformly dispersed in a desired concentration inside the concave portion 804 and inside the cylindrical portion 809.
(Or swollen gel) to fill the region 820 containing the dynamic light scattering system. Highly coherent light from the semiconductor laser 800 is diffused by multiple scattering in the region 820 including the dynamic light scattering system, and travels in the direction of the optical axis 801.

As a method for filling the multiple scattering region, which is the region 820 including the dynamic light scattering system, with a fluid, micropores in which a gas can freely enter and exit but a fluid containing a light scatterer used in the present invention cannot pass. Semipermeable membrane 811 made of permeable polymer
To seal the fluid. First, the region 820 including the dynamic light scattering system is filled with a fluid to fill the cylindrical portion 809,
Cover with a semipermeable membrane 811. At this time, some gas 814 may be mixed. Next, the semipermeable membrane 811 is fixed to the cylindrical portion 809 with a thermosetting or photocurable adhesive 813. A gel or rubber substance 815 is gradually poured onto the semipermeable membrane 811 so that the gas 814 is pushed out through the semipermeable membrane 811. Then, the semipermeable membrane 811
The cylindrical portion 809 sealed by is covered with a gel-like or rubber-like substance 815, and then cured to trap the fluid.

In FIG. 10, the mold portion is the same as that of the eye-safe light source device shown in FIG. 1 of the first embodiment, and the illustration and description thereof are omitted.

(Seventh Embodiment) FIG. 11 is a sectional view showing the arrangement of an eye-safe light source device according to the seventh embodiment of the present invention. In the seventh embodiment, a method of sealing a base material that fills a region including a dynamic light scattering system will be described.

In this eye-safe light source device, as shown in FIG. 11, a resin substrate 903 is provided with a recess 904 having a truncated cone shape expanding upward, and the semiconductor laser 900 is disposed in the recess 904. An Au-plated wiring pattern 907 is formed on the resin substrate 903 and the recess 904, and a lower electrode (not shown) of the semiconductor laser 900 is electrically connected to the Au-plated wiring pattern 907 of the recess 904. On the other hand, an upper electrode (not shown) of the semiconductor laser 900 is electrically connected to an electrode 908 provided on the resin substrate 903 and in the vicinity of the recess 904 via a wire 902. The light scatterer is uniformly dispersed in a desired concentration in the concave portion 904 and the raised portion 905. Highly coherent light from the semiconductor laser 900 diffuses due to multiple scattering in the region (concave portion 904) including the dynamic light scattering system, and travels in the direction of the optical axis 901.

A region including the dynamic light scattering system (recessed portion 904)
As a method for filling the multiple scattering region with
In the region (concave portion 904) including the dynamic light scattering system, the light curable fluid is filled to the extent that a rising portion 905 is formed. Next, the vicinity of the semiconductor laser 900 is kept as a fluid, and only the rising portion 905 is cured so that the fluid does not leak, so that light is mainly irradiated from the side surface. Through the above steps, the fluid can be sealed without mixing the gas. Accordingly, it is not necessary to provide the cylindrical portion, and the manufacturing process can be simplified.
The electrode 908 on the resin substrate 903 may be arranged in the concave portion 904, the raised portion 905, or the mold portion region.

Further, in this seventh embodiment, different substances may be used for the region (recess 904) including the dynamic light scattering system and the raised portion 905. In that case, as an example, it is conceivable that silicone oil is used in the region including the dynamic light scattering system (recess 904) and photocurable silicone gel is used in the raised portion 905. The silicone gel may be thermosetting.

In FIG. 11, the mold portion is the same as that of the eye-safe light source device shown in FIG. 1 of the first embodiment, and the illustration and description thereof are omitted.

(Eighth Embodiment) The light emitted from the eye-safe light source device according to the present invention can be used when transmitting and receiving data between transceivers. FIG. 12 shows a schematic configuration of the optical communication system of the eighth embodiment of the present invention.

In FIG. 12, the transmitter 1000 of the first transceiver 1 is equipped with a transmitter module using the eye-safe light source device of the present invention having a light diffusion structure of a liquid or swollen gel as a transmitter, and a person exists. Incoherent light is emitted in free space. The same applies to the transmitting unit 1004 of the second transceiver 2. Receiving units 1001 and 1002 are mounted on the first transceiver 1 and the second transceiver 2, respectively.
Data is transferred by receiving the incoherent light emitted from 0,1004.

Therefore, even if highly coherent light is emitted from the semiconductor laser, it can be converted into incoherent light at a safe level, so that the optical transmission module of the present invention can be applied to a wireless optical communication system. Become. As described above, by using the semiconductor laser in optical communication, it is possible to reduce the power consumption, reduce the size and the cost, and achieve a high speed and a wide communication area, as compared with the case where the conventional light emitting diode is used as the transmitting means. It is possible to realize an optical communication system having the same.

(Ninth Embodiment) In the eye-safe light source device according to the present invention, if the mold region (epoxy resin mold part) or the region including the dynamic light scattering system is damaged for some reason, eye safety may not be realized. . Therefore, in the ninth embodiment, a configuration is shown in which the eye-safe can be maintained even when the area is damaged.

FIG. 13 is a sectional view showing the structure of the eye-safe light source device according to the ninth embodiment of the present invention. The eye-safe light source device of the ninth embodiment has the same configuration as the eye-safe light source device of the first embodiment except the connection of the wire 1012.

In FIG. 13, 1000 is a semiconductor laser, 1001 is the optical axis of the semiconductor laser 1000,
Reference numeral 02 is a wire, 1003 is a resin substrate, 1004 is a concave portion provided in the resin substrate 1003, 1005 is a molding portion made of epoxy resin as a molding region, 1007.
Is a wiring pattern formed on the resin substrate 1003 and the recess 1004, 1008 is an electrode formed on the resin substrate 1003, 1009 is a cylindrical portion arranged on the resin substrate 1003, 1010 is a cylindrical portion 1009. A metal layer 1011 formed on the inner wall by Ag plating is transparent glass fixed to the upper portion of the cylindrical portion 1009. Inside the recess 1004 and inside the cylindrical portion 1009,
Region 1 in which the light scatterer is filled with a liquid (or swollen gel) uniformly dispersed to a desired concentration and includes a dynamic light scattering system 1.
020 is formed. Region 1 including the dynamic light scattering system
In 020, the light scatterers are uniformly dispersed in a desired concentration.

The mechanism for obtaining incoherent light in the eye-safe light source device is as described in the second embodiment. If the mold part 1005 made of epoxy resin or the dynamic light scattering system 1004 is damaged for some reason, the coherent light from the semiconductor laser 1000 may be emitted to the space without being converted into incoherent light at a sufficiently safe level. is there. here,
It is assumed that the mold part 1005 is peeled off from the resin substrate 1003. As a countermeasure, the wiring pattern 1007
Are partially removed as shown in the drawing, and are connected only by the wire 1012. As a result, when the mold part 1005 is peeled from the substrate, the wire 1012 passing therethrough is cut, so that the coherent light from the semiconductor laser 1000 can be blocked and the eye-safe can be maintained.

(Tenth Embodiment) FIG. 14 shows the first embodiment of the present invention.
It is sectional drawing which shows the structure of the eye-safe light source device of 0th Embodiment, Comprising: Even if a mold area | region (epoxy resin mold part) or the area | region containing a dynamic light-scattering system is damaged, eye-safe can be maintained. . The eye-safe light source device according to the tenth embodiment has a wire 1102.
It has the same configuration as the eye-safe light source device of the seventh embodiment except for the connection.

In FIG. 14, 1100 is a semiconductor laser, 1101 is an optical axis of the semiconductor laser 1100, and 11
Reference numeral 02 is a wire, 1103 is a resin substrate, 1104 is a concave portion provided in the resin substrate 1103, 1105 is a raised portion 1105, 1106 is a mold portion made of epoxy resin as a molding region, 1107 is the resin substrate 1
Wiring patterns 1108 formed on the 103 and the recesses 1104 are electrodes formed on the resin substrate 1003.

Molded portion 110 made of the above epoxy resin
6 or the region including the dynamic light scattering system (recess 1104) is damaged for some reason, the coherent light from the semiconductor laser 1100 may be emitted into the space without being converted into a sufficiently safe level of incoherent light. There is.
Therefore, the wire 1102 connected to the semiconductor laser 1100 is passed into the mold portion 1106. Thereby, the mold portion 1106 or the region including the dynamic light scattering system is formed.
When the (concave portion 1104) is damaged, the wire 11 passing therethrough
Since 02 is cut, the coherent light from the semiconductor laser 1100 can be blocked and the eye-safe can be maintained.

Although the light source device used for optical transmission in free space has been described in the above embodiment, the light source device of the present invention is not limited to this, and may be applied to optical fiber transmission or the like.

[0092]

As is apparent from the above, according to the light source device of the present invention, compared with the case where a gel-like or rubber-like substance is used in the region including the dynamic light-scattering system, it is liquid or swollen. By using the gel, the PAR standard deviation σ of the near-field image can be reduced by approximately one digit or more, and the PAR standard deviation σ required for eye safe can be set to 0.08 or less.

The normalized displacement amount of the light scatterer is approximately λ · 1.
/ 100 can satisfy the eye-safe,
A more desirable value of λ · 2/100 can satisfy the eyesafe. Furthermore, the product of the viscosity of the liquid or swollen gel contained in the dynamic light scattering system and the particle size of the dispersed light scatterer is approximately 1.5 × 10 ⁻¹ Pa · s · μm.
By setting the following, the light intensity of the near-field image can be made eye-safe.

Therefore, even when highly coherent light is emitted from the semiconductor laser, it can be converted into incoherent light at a level safe for human eyes, and therefore the light source device of the present invention can be applied to an optical communication system. It will be possible. Then, by using the semiconductor laser in optical communication, low power consumption and high speed transmission can be realized as compared with the case where the conventional light emitting diode is used.

[Brief description of drawings]

FIG. 1 is a sectional view of an eye-safe light source device according to a first embodiment of the present invention.

FIG. 2 is a graph showing the particle size of a light-scattering body and 3 when the viscosity of a fluid is used as a parameter in the eye-safe light source device.
It is a figure which shows the relationship of the amount (l / lambda) of standardization displacement in 0 ms.

FIG. 3 is a sectional view showing an eye-safe light source device according to a second embodiment of the present invention.

FIG. 4 is a near-field image in the eye-safe light source device.

FIG. 5 is a near-field image when acrylic particles are uniformly dispersed in silicone gel.

FIG. 6 is a sectional view showing an eye-safe light source device according to the third embodiment of the present invention.

FIG. 7 is a sectional view showing an eye-safe light source device according to the fourth embodiment of the present invention.

8A to 8C are schematic views showing a manufacturing process of the eye-safe light source device.

FIG. 9 is a sectional view showing an eye-safe light source device according to the fifth embodiment of the present invention.

FIG. 10 is a sectional view showing an eye-safe light source device according to a sixth embodiment of the present invention.

FIG. 11 is a sectional view showing an eye-safe light source device according to the seventh embodiment of the present invention.

FIG. 12 is a configuration diagram of an optical communication system according to an eighth embodiment of the present invention.

FIG. 13 is a sectional view showing an eye-safe light source device according to the ninth embodiment of the present invention.

FIG. 14 is a sectional view showing an eye-safe light source device according to the tenth embodiment of the present invention.

FIG. 15 is a cross-sectional view showing a configuration of a light source device.

[Explanation of symbols]

100,300,400,500,600,700,800,
900, 1000, 1100 ... Semiconductor laser, 101, 301, 401, 501, 701, 801, 901,
1001, 1101 ... Optical axis of semiconductor laser, 102, 302, 402, 502, 602, 702, 802,
902, 1002, 1012, 1102 ... Wire, 103, 303, 403, 503, 703, 803, 903,
1003, 1103 ... Resin substrate, 104, 304, 504, 604, 704, 804, 904,
1004, 1104 ... Recessed portion, 105, 1005, 1106 ... Molded portion, 107, 307, 407, 507, 707, 807, 907,
1007, 1107 ... Wiring pattern, 108, 508, 708, 808, 908, 1008, 110
8 ... Electrodes, 109, 309, 409, 413, 509, 609, 709,
809, 1009 ... Cylindrical part, 110,310,410,412,510,610,710,
810, 1010 ... Metal layer, 111, 311, 411, 415, 511, 611, 711,
811, 1011 ... Transparent glass, 120, 414, 520, 720, 820, 1020 ... Area including dynamic light scattering system, 308, 408 ... Submount, 404 ... Space, 512 ... Fluid to be dried, 513, 613, 713, 813 ... Adhesive, 714 ... Capillary tube, 814 ... Gas, 815 ... Gel-like or rubber-like substance, 905, 1105.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Atsushi Shimonaka             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Hidenori Kasai             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company F-term (reference) 5F073 AB21 AB25 BA02 EA01 EA29                       FA29 FA30

Claims (11)

[Claims] 1. An optical path of light emitted from a semiconductor light emitting device,
A light source device having a region including a dynamic light scattering system. 2. The light source device according to claim 1, wherein the semiconductor light emitting element is a semiconductor laser. 3. The light source device according to claim 1, wherein the region including the dynamic light scattering system is formed of a liquid including a light scatterer. 4. The light source device according to claim 3, wherein the liquid containing the light scatterer is at least one light scatterer among organic fine particles, fine particles made of silicon oxide, and fine particles made of titanium oxide. A light source device comprising a silicone oil containing: 5. The light source device according to claim 3, wherein the product of the viscosity (Pa · s) of the liquid containing the light scatterer and the particle size (μm) of the dispersed light scatterer is approximately 1.5 × 10 ^-1 Pa · s ・
The light source device is characterized in that it is μm or 1.5 × 10 ⁻¹ Pa · s · μm or less. 6. The light source device according to claim 1, wherein the region including the dynamic light scattering system is formed of swollen gel including a light scatterer. 7. The light source device according to claim 6, wherein the swollen gel containing the light scatterer is a silicone gel swollen by absorbing silicone oil, the fine particles comprising organic fine particles and silicon oxide. And a light source device comprising the above-mentioned silicone gel containing at least one light-scattering body of fine particles of titanium oxide. 8. The light source device according to claim 6, wherein the product of the viscosity (Pa · s) of the swollen gel containing the light scatterer and the particle size (μm) of the dispersed light scatterer is , About 1.5 × 10
⁻¹ Pa · s · μm or 1.5 × 10 ⁻¹ Pa · s · μm or less, a light source device. 9. The light source device according to claim 2, wherein in the light scatterer dispersed in a region including the dynamic light scatterer, the oscillation wavelength of the semiconductor laser is λ, and the light scatterer has a wavelength of 30 ms. The amount of displacement that expresses the spread in time is △
The light source device is characterized in that the normalized displacement Δl / λ depending on the oscillation wavelength of the light scatterer for 30 ms is approximately 1/100 or 1/100 or more. 10. The light source device according to claim 1, further comprising a molding region made of epoxy resin, which covers a region including the dynamic light scattering system, and which is directly or indirectly connected to the semiconductor light emitting device. A light source device characterized in that at least a part of the wire connected to is in the mold region. 11. An optical communication system using the light source device according to claim 1 as a transmitting means.