Communication system using sheet light guide
View Patent ↗In a communication system using a sheet light guide 10 which is formed in a manner that the sheet light guide contains light-scattering particles in a sheet optical medium, and propagates a signal light incident from one end surface thereof to the other end surface side to which a photodetector is coupled, while scattering the signal light by the particles, at least two of the sheet light guides 10 are coupled to each other with an angle-converting light guide 90 interposed therebetween.
1. A communication system using a sheet light guide, which is formed by containing light-scattering particles in a sheet optical medium, and propagates a signal light incident from one end surface thereof to the other end surface side, to which a photodetector is coupled, while scattering the signal light incident from one end surface thereof by the particles,
wherein at least two of the sheet light guides are coupled to each other with an angle-converting light guide interposed therebetween.
2. The communication system using a sheet light guide according to claim 1 , 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.
3. The communication system using a sheet light guide according to claim 2 , 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 taking-out 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 comprising internal transmittivity of the sheet light guide;
when a minimum received optical power P(Reciver_min) dBm is represented as:
P (Receiver_min) dBm =−10Log{ P in· E out·( NPi (min)/ΣNPi)·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 loss coefficient comprising a coupling loss of an optical fiber and the sheet light guide when the optical fiber is coupled to the sheet light guide; and
when a signal voltage determined from the minimum 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 value 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 2 , wherein,
when light taking-out 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 comprising internal transmittivity of the sheet light guide,
when a minimum received optical power P(Reciver_min) dBm is represented as:
P (Receiver_min) dBm =−10Log{ P in· E out·( 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 KT is a loss coefficient comprising a coupling loss of an optical fiber and the sheet light guide when the optical fiber is coupled to the sheet light guide; and
when a signal voltage determined from the minimum 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 value 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.
6. The communication system using a sheet light guide according to claim 2 , wherein, if, in the sheet light guide, the light incident thereonto repeats reflection on respective surfaces other than the incident and emitting end surfaces according to Snell's Law, and if a refractive index of a surrounding medium is Ns, a refractive index of the optical medium as a base material 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.
7. The communication system using a sheet light guide according to claim 2 , wherein, if, in the sheet light guide, a light beam emitted from at least one emitting end surface obeys Snell's Law in reflection and refraction thereof on the emitting end surface, and if a refractive index of a peripheral medium is Ns, a refractive index of the optical medium serving as a mother material 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 2 , wherein the sheet light is formed by mixing non-magnetic conductive particles following the Mie scattering theory into the optical medium.
9. The communication system using a sheet light guide according to claim 2 , wherein the sheet light guide is formed by mixing the particles into the optical medium while a gradient is being given to a particle density thereof.
10. The communication system using a sheet light guide according to claim 2 , wherein the sheet light guide is formed by combining a plurality of the optical mediums.
11. The communication system using a sheet light guide according to claim 1 , wherein, if, in the sheet light guide, the light incident thereonto repeats reflection on respective surfaces other than the incident and emitting end surfaces according to Snell's Law, and if a refractive index of a surrounding medium is Ns, a refractive index of the optical medium as a base material 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 1 , wherein, if, in the sheet light guide, a light beam emitted from at least one emitting end surface obeys Snell's Law in reflection and refraction thereof on the emitting end surface, and if a refractive index of a surrounding medium is Ns, a refractive index of the optical medium serving as a base material 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.
13. The communication system using a sheet light guide according to claim 1 , wherein the sheet light is formed by mixing non-magnetic conductive particles following the Mie scattering theory into the optical medium.
14. The communication system using a sheet light guide according to claim 1 , wherein the sheet light guide is formed by mixing the particles into the optical medium while a gradient is being given to a particle density thereof.
15. The communication system using a sheet light guide according to claim 1 , wherein the sheet light guide is formed by combining a plurality of the optical mediums.