Optical transmitting apparatus and optical repeating apparatus

An optical repeating apparatus comprising:

• a first optical transmitting means for receiving first transmission light (λ1L) and first pumping light (λ2PL) transmitted from an optical transmitting apparatus through a first optical fiber, amplifying the first transmission light (λ1L) and the first pumping light (λ2PL), and outputting second transmission light (λ1L′) and second pumping light (λ2PL′);
• a first loopback means, connected to said first optical transmitting means, for extracting the second pumping light (λ2PL′) from the optical signal amplified by said first optical transmitting means, and outputting the second pumping light (λ2PL′);
• a second optical transmitting means for receiving third transmission light (λ1R) and third pumping light (λ3PR) transmitted from an optical receiving apparatus through said second optical fiber, amplifying the third transmission light (λ1R) and the third pumping light (λ3PR), and outputting fourth transmission light (λ1R′);
• a second loopback means, connected to said second optical transmitting means, for extracting fourth pumping light (λ3PR′) from the optical signal amplified by said second optical transmitting means, and outputting the fourth pumping light (λ3PR′);
• a first optical coupler, disposed on an output's side of said first optical transmitting means, for outputting the second transmission light (λ1L′) and the second pumping light (λ2PL′) toward the side of said optical receiving apparatus, while outputting the third transmission light (λ1R) and the third pumping light (λ3PR) from the side of said optical receiving apparatus;
• and
• a second optical coupler, disposed on an output's side of said second optical transmitting means, for outputting the optical signal from said first loopback means and the optical signal from said second optical transmitting means toward a side of said optical transmitting apparatus, while outputting the first transmission light (λ1L) and the first pumping light (λ2PL) from a side of said optical transmitting apparatus.

An optical transmitting apparatus comprising:

• an optical transmitter multiplexing first transmission light and first pumping light and thereby amplifying the first transmission light, and outputting an amplified optical signal to an internal optical fiber;
• a level monitor, connected to said optical transmitter, detecting a level of the optical signal outputted from said optical transmitter;
• an optical multiplexer, connected to said internal optical fiber, transmitting an optical signal in said internal optical fiber to a first optical fiber connected to an external optical repeating apparatus, and also being operable to receive an optical signal having a predetermined wavelength in transmission light transmitted from said external optical repeating apparatus through said first optical fiber, and splitting the optical signal into a plurality of directions, and outputting a split optical signal;
• and
• a loopback light detector, connected to said optical multiplexer, receiving an optical monitoring signal transmitted from said external optical repeating apparatus.

An optical repeating apparatus comprising:

• a first optical transmitter receiving first transmission light and first pumping light transmitted from an optical transmitting apparatus through a first optical fiber, amplifying the first transmission light and the first pumping light, and outputting second transmission light and second pumping light;
• a first loopback device, connected to said first optical transmitter, extracting the second pumping light from the optical signal amplified by said first optical transmitter, and outputting the second pumping light;
• a second optical transmitter receiving third transmission light and third pumping light transmitted from an optical receiving apparatus through a second optical fiber, amplifying the third transmission light and the third pumping light, and outputting fourth transmission light;
• a second loopback device, connected to said second optical transmitter, extracting fourth pumping light from the optical signal amplified by said second optical transmitter, and outputting the fourth pumping light;
• a first optical coupler, disposed on an output's side of said first optical transmitter, outputting the second transmission light and the second pumping light toward the side of said optical receiving apparatus, while outputting the third transmission light and the third pumping light from the side of said optical receiving apparatus;
• and
• a second optical coupler, disposed on an output's side of said second optical transmitter, outputting the optical signal from said first loopback device and the optical signal from said second optical transmitter toward a side of said optical transmitting apparatus, while outputting the first transmission light and the first pumping light from a side of said optical transmitting apparatus.