Sheet-shaped light guide and communication system using the same
View Patent ↗In a sheet-shaped light guide ( 95 ), which includes particles for scattering light in a sheet-shaped optical medium and propagates signal light incident from one end face of the sheet-shaped light guide to the other end face side while scattering the signal light by the particles, a high-refractive-index portion 95 a and a low-refractive-index portion 95 b are formed by the use of a plurality of optical mediums whose refractive indexes are different from each other. Then, an interface between these high-refractive-index portion 95 a and low-refractive index portion 95 b is curved, and a lens effect for the signal light is imparted.
1. A sheet-shaped light guide, which includes particles for scattering light in a sheet-shaped optical medium and propagates signal light incident from one end face of the sheet-shaped light guide to the other end face side while scattering the signal light by the particles,
wherein a plurality of optical mediums whose refractive indexes are different from each other are used as the optical medium, and
an interface between the optical mediums is formed into a curved shape, and has a concave lens effect for the signal light,
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 , 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, and
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 communication system satisfies:
Pr(Noise(System_rms)·Q)≦BER(accept)
where Q is a proportionality constant.
2. A sheet-shaped light guide, which includes particles for scattering light in a sheet-shaped optical medium and propagates signal light incident from one end face of the sheet-shaped light guide to the other end face side while scattering the signal light by the particles,
wherein a plurality of optical mediums whose refractive indexes are different from each other are used as the optical medium, and
an interface between the optical mediums is formed into a curved shape, and has a concave lens effect for the signal light,
wherein, in the interface, the optical medium whose refractive index is higher forms a concave shape toward the optical medium whose refractive index is lower, thus realizing the concave lens effect at the interface;
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 , 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, and
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 communication system satisfies:
Pr(Noise(System_rms)·Q)≦BER(accept)
where Q is a proportionality constant.
3. A sheet-shaped light guide, which includes particles for scattering light in a sheet-shaped optical medium and propagates signal light incident from one end face of the sheet-shaped light guide to the other end face side while scattering the signal light by the particles,
wherein a plurality of optical mediums whose refractive indexes are different from each other are used as the optical medium, and
an interface between the optical mediums is formed into a curved shape, and has a concave lens effect for the signal light;
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 , 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, and
wherein, when light emission efficiency Eout in the sheet-shaped 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 aggregating internal transmissivity and the like of the sheet-shaped light guide,
a minimum received optical power P(Receiver_min)dBm of a light receiver is represented as:
P (Receiver_min) dBm =−10Log{ P in ·E out·( NPi (min)/Σ NPi )·π/4}· K T
where Pin is received optical power, NPi(min) is optical power of a segment in which optical power becomes minimum, ΣNPi is a sum of the optical power of respective segments, and K T is a coupling loss between a light emitter, optical fibers, a light receiver and the like, and
a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistor of a light receiver is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold value in binarization is V(Thresh),
the communication system satisfies:
{ S ( PRmin ) v−V ( Thresh )}> Noise ( System — rms )· Q.
4. A sheet-shaped light guide, which includes particles for scattering light in a sheet-shaped optical medium and propagates signal light incident from one end face of the sheet-shaped light guide to the other end face side while scattering the signal light by the particles,
wherein a plurality of optical mediums whose refractive indexes are different from each other are used as the optical medium, and
an interface between the optical mediums is formed into a curved shape, and has a concave lens effect for the signal light,
wherein, in the interface, the optical medium whose refractive index is higher forms a concave shape toward the optical medium whose refractive index is lower, thus realizing the concave lens effect at the interface;
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 , 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;
wherein, when light emission efficiency Eout in the sheet-shaped light guide is represented as:
Eout =exp{−(Φ· Np·L G ·K C )}· K L ,
where K L is a loss coefficient obtained by aggregating internal transmissivity and the like of the sheet-shaped light guide,
a minimum received optical power P(Receiver_min)dBm of a light receiver is represented as:
P ( Receiver _min) dBm =−10Log{ Pin·Eout ·( NPi (min)/Σ NPi )·π/4}· K T
where Pin is received optical power, NPi(min) is optical power of a segment in which optical power becomes minimum, ΣNPi is a sum of the optical power of respective segments, and K T is a coupling loss between a light emitter, optical fibers, a light receiver and the like, and
a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistor of a light receiver is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold value in binarization is V(Thresh),
the communication system satisfies:
{S(PRmin)v−V(Thresh)}>Noise(System_rms)·Q.
5. The communication system using the sheet-shaped light guide according to claim 1 ,
wherein, when light emission efficiency Eout in the sheet-shaped 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 aggregating internal transmissivity and the like of the sheet-shaped light guide,
a minimum received optical power P(Receiver_min) dBm of a light receiver is represented as:
P (Receiver_min) dBm =−10Log{ P in· E out·( NPi (min)/Σ NPi )·π/4}· K T
where Pin is received optical power, NPi(min) is optical power of a segment in which optical power becomes minimum, ΣNPi is a sum of the optical power of respective segments, and K T is a coupling loss between a light emitter, optical fibers, a light receiver and the like, and
a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistor of a light receiver is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold value in binarization is V(Thresh),
the communication system satisfies:
{S(PRmin)v−V(Thresh)}>Noise(System_rms)·Q.
6. The communication system using the sheet-shaped light guide according to claim 2 ,
wherein, when light emission efficiency Eout in the sheet-shaped 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 aggregating internal transmissivity and the like of the sheet-shaped light guide,
a minimum received optical power P(Receiver_min) dBm of a light receiver is represented as:
P (Receiver_min) dBm =−10Log{ P in ·E out·( NPi (min)/Σ NPi )·π/4 }·K T
where Pin is received optical power, NPi(min) is optical power of a segment in which optical power becomes minimum, ΣNPi is a sum of the optical power of respective segments, and K T is a coupling loss between a light emitter, optical fibers, a light receiver and the like, and
a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistor of a light receiver is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold value in binarization is V(Thresh),
the communication system satisfies:
{S(PRmin)v−V(Thresh)}>Noise(System_rms)·Q.
7. A sheet-shaped light guide, which includes particles for scattering light in a sheet-shaped optical medium and propagates signal light incident from one end face of the sheet-shaped light guide to the other end face side while scattering the signal light by the particles,
wherein a plurality of optical mediums whose refractive indexes are different from each other are used as the optical medium, and
an interface between the optical mediums is formed into a curved shape, and has a concave lens effect for the signal light;
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 communication system satisfies:
Pr(Noise(System_rms)·Q)≦BER(accept)
where Q is a proportionality constant.
8. A sheet-shaped light guide, which includes particles for scattering light in a sheet-shaped optical medium and propagates signal light incident from one end face of the sheet-shaped light guide to the other end face side while scattering the signal light by the particles,
wherein a plurality of optical mediums whose refractive indexes are different from each other are used as the optical medium, and
an interface between the optical mediums is formed into a curved shape, and has a concave lens effect for the signal light;
wherein, when light emission efficiency Eout in the sheet-shaped 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 aggregating internal transmissivity and the like of the sheet-shaped light guide,
a minimum received optical power P(Receiver_min)dBm of a light receiver is represented as:
P (Receiver_min) dBm =−10Log { P in· E out( NPi (min)/ ΣNPi )·π/4 } K T
where Pin is received optical power, NPi(min) is optical power of a segment in which optical power becomes minimum, ΣNPi is a sum of the optical power of respective segments, and K T is a coupling loss between a light emitter, optical fibers, a light receiver and the like, and
a signal voltage determined from the minimum received optical power P(Receiver_min) dBm and a load resistor of a light receiver is S(PRmin)v, rms noise of the system is Noise(System_rms), and an arbitrary threshold value in binarization is V(Thresh),
the communication system satisfies:
{S(PRmin)v−V(Thresh)}>Noise(System_rms)·Q.