Abstract: An optical signal monitoring and control method including receiving a first optical signal, performing optical-to-electrical conversion on the first optical signal, and outputting a converted first electrical signal, monitoring the first electrical signal, and acquiring a monitored power of the first electrical signal, adjusting the monitored power of the first electrical signal according to a target monitored power of the first electrical signal, and outputting a second electrical signal, and performing optical-to-electrical conversion on the second electrical signal according to a correspondence between the target monitored power of the first electrical signal and a target extinction ratio of the first optical signal, and outputting a converted second optical signal, where the second optical signal is an optical signal that has a target extinction ratio. The method implements precise control on an extinction ratio of an optical signal.

Abstract: A method for testing an optical fiber includes: receiving a test optical signal from an optical fiber network, and converting the test optical signal into a test current signal; receiving, by a transimpedance amplifier, the test current signal by using a first working mode and outputting a first test voltage signal; acquiring a swing of the first test voltage signal, and determining whether the swing of the first test voltage signal meets a preset condition; and receiving, by the transimpedance amplifier, the test current signal by using a second working mode and outputting a second test voltage signal when the swing of the first test voltage signal meets the preset condition, where an upper limit and a lower limit of a receiver dynamic range when the transimpedance amplifier works in the first working mode are different from those when the transimpedance amplifier works in the second working mode.

Abstract: Embodiments of the present disclosure disclose an OTDR test signal modulation circuit, including a laser diode drive, a laser diode, a current adjusting unit, and an OTDR control unit. The laser diode drive is connected to the laser diode and is configured to drive, according to an input data signal, the laser diode to transmit data light. The current adjusting unit is connected to the laser diode and the OTDR control unit and is configured to adjust a current flowing through the laser diode according to an OTDR test signal provided by the OTDR control unit, so as to modulate the OTDR test signal to the data light transmitted by the laser diode. Moreover, the embodiments of the present disclosure also disclose a passive optical network system and apparatus.

Abstract: A method can be used for controlling optical power. Output optical power of an optical source is monitored and it is determined whether a preset test control signal is received. When the preset test control signal is not received, a data signal is modulated to output light of the optical source and a bias current of the optical source is adjusted according to an output optical power monitoring result of the optical source to implement automatic power control. When the preset test control signal is received, a test is started and a test signal is superimposed to the data signal to form a superimposed signal. The superimposed signal is modulated to the output light of the optical source. The output optical power monitoring result of the optical source is ignored during the test period to maintain the bias current of the optical source at a preset target value.

Abstract: A method for testing an optical fiber includes: receiving a test optical signal from an optical fiber network, and converting the test optical signal into a test current signal; receiving, by a transimpedance amplifier, the test current signal by using a first working mode and outputting a first test voltage signal; acquiring a swing of the first test voltage signal, and determining whether the swing of the first test voltage signal meets a preset condition; and receiving, by the transimpedance amplifier, the test current signal by using a second working mode and outputting a second test voltage signal when the swing of the first test voltage signal meets the preset condition, where an upper limit and a lower limit of a receiver dynamic range when the transimpedance amplifier works in the first working mode are different from those when the transimpedance amplifier works in the second working mode.

Abstract: The present invention is directed to a reinforced absorbable hemostat comprising at least one hemostatic agent in a single layer of nonwoven synthetic fabric having a mixture of compressed fiber staples of a polyglycolide/polylactide copolymer and a polydioxanone.

Abstract: The present invention is directed to a reinforced absorbable hemostat comprising at least one hemostatic agent in a single layer of nonwoven synthetic fabric having a mixture of compressed fiber staples of a polyglycolide/polylactide copolymer and a polydioxanone.

Abstract: The present invention is directed to a synthetic fabric comprising a multi-layered nonwoven fabric made from staples of a polyglycolide/polylactide copolymer, each layer having a different density. The multi-layer fabric can be used as a reinforced absorbable hemostat medical device.

Abstract: The present invention is directed to a reinforced absorbable hemostat comprising at least one hemostatic agent in a single layer of nonwoven synthetic fabric having a mixture of compressed fiber staples of a polyglycolide/polylactide copolymer and a polydioxanone.

Abstract: The present invention is directed to a reinforced absorbable hemostat comprising at least one hemostatic agent in a single layer of nonwoven synthetic fabric having a mixture of compressed fiber staples of a polyglycolide/polylactide copolymer and a polydioxanone.

Abstract: The present invention is directed to a synthetic fabric comprising a multi-layered nonwoven fabric made from staples of a polyglycolide/polylactide copolymer, each layer having a different density. The multi-layer fabric can be used as a reinforced absorbable hemostat medical device.