Communication system using sheet light guide
View Patent ↗In a communication system using a sheet light guide ( 10 ) which is formed to contain light-scattering particles in a sheet optical medium and propagates signal light incident from one end surface thereof to the other end surface side while scattering the signal light by the particles, a photodetector ( 55 ) which is coupled to the other end surface of the sheet light guide ( 10 ) and detects the signal light and a demultiplexer ( 84 ) which distributes an output of the photodetector ( 55 ) to a plurality of lines are provided.
1. A communication system using a sheet light guide, which is formed to contain light-scattering particles in a sheet optical medium, and propagates signal light incident from one end surface thereof to the other end surface side while scattering the signal light by the particles, the system comprising:
a photodetector which is coupled to the other end surface of the sheet light guide and detects the signal light; and
a demultiplexer which distributes an output of the photodetector to a plurality of lines,
wherein, when a scattering cross section of the particles is Φ, a length of the optical medium in a light propagation direction is L G , a particle density is Np, and a correction coefficient is K C , a value of Φ·Np·L G ·K c is 0.9 or less.
2. The communication system using a sheet light guide according to claim 1 , wherein,
when light extraction efficiency Eout in the sheet light guide is represented as:
Eout=exp{−(Φ· Np·L G K C )} K L
where K L is a loss coefficient obtained by synthesizing internal transmissivity and the like of the sheet light guide,
when a minimum received optical power P(Receiver_min) dBm is represented as:
P
(
Receiver_min
)
dBm
=
-
10
Log
{
Pin
•
Eout
•
(
NPi
(
min
)
/
Σ
NPi
)
•π
/
4
}
•K
T
where Pin is incident optical power, NPi(min) is optical power of a segment in which the optical power becomes minimum, ΣNPi is a sum of optical powers of respective segments, and K T is a coupling loss of a light emitter, optical fibers, the photodetector and the like, and
when a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistance of the photodetector is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold in binarization is V(Thresh),
the following is satisfied:
{S ( PR min) v−V (Thresh)}>Noise(System_rms)· Q
where Q is a proportionality constant.
3. The communication system using a sheet light guide according to claim 1 , wherein, when rms noise of the system is Noise(System_rms), an acceptable bit error rate is BER(accept), and a probability of occurrence of the Noise(System_rms) is Pr(Noise(System_rms)), the following is satisfied:
Pr(Noise(System_rms)· Q )≦ BER (accept)
where Q is a proportionality constant.
4. The communication system using a sheet light guide according to claim 3 , wherein,
when light extraction efficiency Eout in the sheet light guide is represented as:
E out=exp{−(Φ· Np·L G K C )}· K L
where K L is a loss coefficient obtained by synthesizing internal transmissivity and the like of the sheet light guide,
when a minimum received optical power P(Receiver_min) dBm is represented as:
P
(
Receiver_min
)
dBm
=
-
10
Log
{
Pin
•
Eout
•
(
NPi
(
min
)
/
Σ
NPi
)
•π
/
4
}
•K
T
where Pin is incident optical power, NPi(min) is optical power of a segment in which the optical power becomes minimum, ΣNPi is a sum of optical powers of respective segments, and K T is a coupling loss of a light emitter, optical fibers, the photodetector and the like, and
when a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistance of the photodetector is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold in binarization is V(Thresh),
the following is satisfied:
{S ( PR min) v−V (Thresh)}>Noise(System_rms)· Q.
5. The communication system using a sheet light guide according to claim 1 , wherein the sheet light guide comprises a plurality of optical media.
6. The communication system using a sheet light guide according to claim 1 , wherein the sheet light guide comprises a mixture of non-magnetic conductive particles following the Mie scattering theory and the optical medium.
7. The communication system using a sheet light guide according to claim 2 , wherein, when it is assumed that, in the sheet light guide, the light incident thereonto repeats reflection on respective surfaces other than incident/emitting end surfaces according to Snell's Law, and when a refractive index of a surrounding medium is Ns, a refractive index of the optical medium as a matrix is Nm, an incident angle is θm, and a refraction angle is θs, if Nm·sin θm=Ns·sin θs is established in the case where the particles are not contained, the sheet light guide is formed of an optical medium with a shape satisfying sin θs>1.
8. The communication system using a sheet light guide according to claim 1 , wherein,
when light extraction efficiency Eout in the sheet light guide is represented as:
Eout=exp{−(Φ· Np·L G ·K C )}· K L
where K L is a loss coefficient obtained by synthesizing internal transmissivity and the like of the sheet light guide,
when a minimum received optical power P(Receiver_min) dBm is represented as:
P
(
Receiver_min
)
dBm
=
-
10
Log
{
Pin
•
Eout
•
(
NPi
(
min
)
/
Σ
NPi
)
•π
/
4
}
•K
T
where Pin is incident optical power, NPi(min) is optical power of a segment in which the optical power becomes minimum, ΣNPi is a sum of optical powers of respective segments, and K T is a coupling loss of a light emitter, optical fibers, the photodetector and the like, and
when a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistance of the photodetector is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold in binarization is V(Thresh),
the following is satisfied:
{ S ( PR min) v−V (Thresh)}>Noise(System_rms) ·Q.
9. The communication system using a sheet light guide according to claim 1 , wherein. when it is assumed that, in the sheet light guide, a light beam emitted from at least one emitting end surface obeys Snell's Law in reflection/refraction thereof on the emitting end surface, and when a refractive index of a surrounding medium is Ns, a refractive index of the optical medium serving as a matrix is Nm, an incident angle is θm, and a refraction angle is θs, if Nm·sin θm=Ns·sin θs is established in the case where the particles are not contained, the sheet light guide is formed of an optical medium with a shape satisfying sin θs<1.
10. A communication system using a sheet light guide, which is formed to contain light-scattering particles in a sheet optical medium, and propagates signal light incident from one end surface thereof to the other end surface side while scattering the signal light by the particles, the system comprising:
a photodetector which is coupled to the other end surface of the sheet light guide and detects the signal light; and
a demultiplexer which distributes an output of the photodetector to a plurality of lines,
wherein the sheet light guide comprises a mixture of non-magnetic conductive particles following the Mie scattering theory and the optical medium.
11. The communication system using a sheet light guide according to claim 10 , wherein, when it is assumed that, in the sheet light guide, the light incident thereonto repeats reflection on respective surfaces other than incident/emitting end surfaces according to Snell's Law, and when a refractive index of a surrounding medium is Ns, a refractive index of the optical medium as a matrix is Nm, an incident angle is θm, and a refraction angle is θs, if Nm·sin θm=Ns·sin θs is established in the case where the particles are not contained, the sheet light guide is formed of an optical medium with a shape satisfying sin θs>1.
12. The communication system using a sheet light guide according to claim 10 , wherein the sheet light guide comprises a mixture of the particles and the optical medium with a particle density gradient.
13. The communication system using a sheet light guide according to claim 10 , wherein the sheet light guide comprises a mixture of the particles and the optical medium with a particle density gradient.
14. The communication system using a sheet light guide according to claim 10 , wherein the sheet light guide comprises a plurality of optical media.
15. The communication system using a sheet light guide according to claim 10 , wherein, when it is assumed that, in the sheet light guide, a light beam emitted from at least one emitting end surface obeys Snell's Law in reflection/refraction thereof on the emitting end surface, and when a refractive index of a surrounding medium is Ns, a refractive index of the optical medium serving as a matrix is Nm, an incident angle is θm, and a refraction angle is θs, if Nm·sin θm=Ns·sin θs is established in the case where the particles are not contained, the sheet light guide is formed of an optical medium with a shape satisfying sin θs<1.
16. The communication system using a sheet light guide according to claim 10 , wherein, when rms noise of the system is Noise(System_rms), an acceptable bit error rate is BER(accept), and a probability of occurrence of the Noise(System_rms) is Pr(Noise(System_rms)), the following is satisfied:
Pr (Noise(System_rms)· Q )≦ BER (accept)
where Q is a proportionality constant.