RFTV is a unidirectional analogue and digital video broadcast. It adopts high efficiency modulation mode for RF carrier wave and its economical efficiency, flexibility and bandwidth validity is beyond comparison of IPTV. By adopting EPON, GEPON or P2P access mode to realize triple-play and FTTx, RFTV broadcasting network in 1550nm optical wavelength still plays an important role and 1550nm externally modulated optic transmitter is the core equipment in this system.

1550nm externally modulated optic transmitter technology has no laser chirp, low dispersion distortion, and great extinction rate, with excellent characteristic within 40~862MHz. External Modulator doesn't generate CSO distortion after reasonable bias. It can be connected by amplifiers when applied in large area coverage of over-long trunk and local networks. Adopting WDM, it can multiplex optical channels with multi-wavelength through one fiber. 1550nm optic transmitter CATV follows the current development trend of triple-play and fiber to home.

Huatai is the well-known manufacture in analog externally modulated optic transmitter around the world. HT8500T is a series of 1550nm externally modulated optic transmitter achieving the highest standards of today. The whole-unit's optical source adopts narrow line width (Typ.=0.3MHz), low noise and continuous wave DFB laser, which is propitious to reduce dispersion effect. Adopting ITU standard wavelength, users can adjust and set the wavelength on the front panel within the range of ±200GHz (±1.6nm) as ±0.05nm stepping. HT8500T EM optic transmitter is applicable for the network upgrading and expansion of WDM system. The whole unit signal modulation adopts CATV special LiNbO3 external modulator of American JDS-U company and Huatai optimized control technology with independent intellectual property , so HT8500T EM optic transmitter can reach high index of back to back CNR ≥ 54dB, CTB ≤ -65dB, CSO ≤ -65dB, SBS: 13~19dBm continuous adjustable. The whole unit is equipped with perfect RS232 communication interface, SNMP network management, 1+1 back-up power supply , hot-plug function available, chassis temperature auto-control. All the optical port of EM optic transmitter can be installed in the front panel (The back panel is also available if needed).

Huatai HT8500T, top type externally modulated optic transmitter with it's high index, high reliability and excellent cost performance, is applicable for the over-long trunk of large and middle CATV station head-end, WDM system and CFG dispersion compensation system.

  HT8527T :  2 fiber output, each port ≥7.0dBm, CNR ≥ 54.0dB、SBS: 13~19dBm

continuously adjustable、ITU wavelength adjustable.

  HT8529T :  2 fiber output, each port ≥8.5dBm, CNR ≥ 54.0dB、SBS: 13~19dBm

continuously adjustable、ITU wavelength adjustable.

  HT85210T :  2 fiber output, each port ≥10dBm, CNR ≥ 54.0dB、SBS: 13~19dBm

continuously adjustable、ITU wavelength adjustable.

  HT85212T :  2 fiber output, each port ≥12dBm, CNR ≥ 54.0dB、SBS: 13~19dBm

continuously adjustable、ITU wavelength adjustable.

  HT85213T :  2 fiber output, each port ≥13dBm, CNR ≥ 54.0dB、SBS: 13~19dBm

continuously adjustable、ITU wavelength adjustable.

 Externally modulated technology for HT8500T optic transmitter, no laser chirp, low

dispersion distortion, high extinction ratio, with excellent characteristic within 40~862MHz, used in the over-long trunk of large and medium sized cable television head-end.

 1+1 powers supply back , up hot-plug function available.

 Narrow line width (Typ=0.3 MHz), low noise, and DFB continuous wave laser, be

propitious to reduce dispersion effect.

 The work bandwidth for HT8500T optic transmitter is up to 47~862MHz.

 CNR ≥ 54dB and excellent CTB, CSO index.

 SBS: 13~19dBm, continuous adjustable.

 ITU standard wavelength adjustable , users can adjust and set the wavelength on the

front panel with ±0.05nm stepping in the range of ±200GHz (±1.6nm), used in the network upgrading and expansion of WDM system.

 AGC/MGC mode is optional at spot; OMI can be optimized at spot.

 Perfect RS232 communicate interface.

 Advanced SNMP network management function.

 Casing temperature auto-control.

 Used in the over-long trunk and distribution net in the large and middle cable television

central station head-end.

      Analogue digital hybrid transmission > 200Km (with dispersion compensation).

      Pure digital transmission (Without dispersion compensation) > 400Km,

                                                     (With dispersion compensation) >700Km.

 VAS in DWDM fiber CATV system

 CFG dispersion compensates system.

 255Km PAL-D/56CH & 20CH Digital QAM Hybrid Transmission Application Cases

 587Km pure digital TV 1550nm overlength optical trunk application Cases