External modulation technology for HT1500B 1550nm transmitter, with the laser working in direct current, has the advantages of no laser chirp, low dispersion distortion, large extinction ratio, and high speed. 1550nm transmitter also has the disadvantages of high cost and high difficulty in manufacturing.
Direct modulation will lead to high laser chirp (Laser's bias current is modulated by signal and the optical spectrum shifts and shakes). Laser chip will interact with dispersion effect caused by standard single mode fiber (SMF-28), which will generate serious distortion in the place of 1550nm. This kind of distortion will become more serious with the increase of transmission distance, bandwidth and channel number.
At present, international high performance direct modulation 1550nm transmitter has no obvious performance inferior while transmitting an analog and digital multiplexing full channel signal with transmission distance≤15Km or transmitting digital load with transmission distance≤40Km.
Huatai HT1500B is a direct modulation 1550nm transmitter with high index and without AGC function. It adopts high linearity and low chirp DFB laser, built-in pre-distortion compensation and AGC, APC, ATC closed loop control, which improves the system index obviously. The 1550nm transmitter can be used in FTTx (≤10Km) of second-grade service area (Sub-HE), and can also be used in WDM narrow-band multiplexing and IP/QAM.
HT1500BC 1550nm transmitter: CATV wavelength.
HT1500BU 1550nm transmitter: ITU standard wavelength.
Low chirp, high linearity DFB laser.
Dual module RF driver, high efficient laser pre-distortion adjustment.
Perfect APC, ATC closed loop control.
Intuitionistic modulation status display.
Built-in dual back-up power supply, switch automatically.
Casing temperature auto-control, ensure the long life of the laser.
Provide IPTV, VOD value-added service in second-grade service area (Sub-HE).
Analog digital mixed transmit <15Km. (common distance ≤ 10km).
Pure digital load <40Km.
DWDM narrow band multiplex >70Km.