• 1550nm External Modulation Optical Transmitter
    • Model Number: ST1550E
    • Brand: SOFTEL
    • MOQ: 1 PCS
     

    1.0 Product description 

    1550nm externally modulated optical transmitter is the core equipment in the RFTV network system. RFTV is a unidirectional analogue and digital video broadcast. It adopts high efficiency modulation mode for RF carrier wave and its economy, 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.

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

    ST1550E that accords with current international industry technique standard is a 1550nm Externally Modulated Optical Transmitter. The whole unit light source adopts narrow bandwidth (0.65MHz ), low noise, continuous wave DFB laser, which is propitious to reduce the influence of dispersion. The whole unit signal modulation adopts CATV special LiNbO3 external modulator of American company and optimized control technology with independent intellectual property , so it can reach high index of back to back CNR ≥ 54dB, CTB ≤ -65dB, CSO ≤ -65dB, SBS: 13~18dBm 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.

    ST1550E, advanced type externally modulated optical transmitter with it's high index, high reliability and excellent cost performance, is applicable for main links and distribution network links in large and middle CATV station head-end.

    • ST1550E-2-5: 2 fiber output, each port ≥4.5dBm, CNR ≥ 53.0dB, SBS: 13~18dBm continuously adjustable, ITU wavelength adjustable.

    • ST1550E-2-7: 2 fiber output, each port ≥7.0dBm, CNR ≥ 53.0dB, SBS: 13~18dBm continuously adjustable、ITU wavelength adjustable.

    • ST1550E-2-9: 2 fiber output, each port ≥8.5dBm, CNR ≥ 53.0dB, SBS: 13~18dBm continuously adjustable、ITU wavelength adjustable.

    • ST1550E-2-10:: 2 fiber output, each port ≥10dBm, CNR ≥ 53.0dB, SBS: 13~18dBm continuously adjustable, ITU wavelength adjustable.

    • ST1550EU: ITU standard wavelength adjustable. User can adjust and set the laser wavelength within ±200GHz (±1.6nm) at ±0.05nm space by LCD menu or buttons on the front panel. Apply to WDM network upgrade and expansion.

     

    2.0 Product feature

    • High performance: Externally modulated technology, no laser chirp, low dispersion distortion, high extinction ratio, with excellent characteristic within 40~862MHz.

    • Narrow bandwidth (0.65MHz), lower noise, DFB continuous wave laser, is propitious to reduce the influence of the dispersion.

    • The operating bandwidth is up to 47~862MHz (47~1080MHz).

    • CNR ≥ 53dB and excellent CTB, CSO index.

    • SBS: 13~18dBm adjustable.

    • ITU standard wavelength, ±200GHz (±1.6nm) adjustable.

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

    • Perfect RS232 communication interface.

    • Advanced SNMP network management function.

    • 1+1 power supply backup, switch automatically.

    • Casing temperature auto-control.

    • Excellent P/P ratio.

     

     

     

     

    3.0 Main application

    • Used in main links and distribution network links in large and middle CATV station head-end.
    Analog digital hybrid transmission >200Km (with dispersion compensation).
    Pure digital transmission (without dispersion compensation) >400Km,
                             (with dispersion compensation) >700Km.

    • ST1550EU ITU wavelength adjustable, applicable to the value-added service of DWDM fiber optic CATV system and CFG dispersion compensation system.

    • It can be used in branch FTTH that has high system index demand. Point to Point>65Km, CSO ≤ -65dB. It can provide high qualified and reliable value-added service such as RFTV, IPTV and VOD for the secondary users. It can also avoid the limitation of CSO deterioration and transmission distance caused by laser chirp for adopting 1550nm direct modulated optical transmitter.

     

    4.0 TECHNIQUE INDEX

    Performance

    Index

    Supplement

    Optic feature

    Operating wavelength

    (nm)

    1548~1563

    ST1550EC

    ITU-TG.692

    ST1550EU

    Wavelength ADJ. range

    (nm)

    ±1.6(±200GHz)

    ST1550EC

    Wavelength ADJ. mode

     

    ±0.05nm stepping

    ST1550EU

    Wavelength stability

    (Pm/℃)

    -1~0

    Tc=20~70℃

    Linewidth

    (MHz)

    Typ.=0.65

    FWHM(△λ), (-3dB fullwidth)

    Side mode suppression ratio

    (dB)

    ≥45

    SMSR

    Equivalent noise intensity

     

    ≤-160

    RIN(20~1000MHz)

    Number of output port

     

    2

    Optional4,6

    Output power

    (dBm)

    10, 8.5, 7.0, 4.5

    2×7, 2×9, 2×10, 2×5, 4×7,6×7

    Return loss

    (dB)

    ≥50

     

    Optical  connector

     

    FC/APC

    Optional SC/APC, LC/APC

    RF  feature

    Work bandwidth

    (MHz)

    47~862

     

    Input level

    (dBmV)

    18~28

    AGC

    Flatness

    (dB)

    ≤±0.75

    47~862MHz

    Return loss

    (dB)

    >16

     

    Input impedance

    (Ω)

    75

     

    RF port

     

    F-Female

     

    Link feature

    Transmit channel

     

    PAL-D/60CH

    PAL-D/99CH

     

    CNR1

    (dB)

    ≥53.0

    ≥51.5

    Back to Back

    CNR2

    (dB)

    ≥51.5

    ≥49.5

    65Km optical fiber, 0dBm receive

    CTB

    (dB)

    ≥-65

    ≥-65

     

    CSO

    (dB)

    ≥-65

    ≥-65

     

    SBS restrain

    (dBm)

    13~18

    Adjustable

    General feature

    SNMP network management interface

     

    RJ45

     

    Communication interface

     

    RS232

     

    Power supply

    (VAC)

    90~265

    50/60Hz

    (VDC)

    -48

    30~72VDC

    Power consume

    (W)

    50

    Single power works

    Work temp.

    (℃)

    -5~65

    Machine temp. control automatically

    Storage temp.

    (℃)

    -40~85

     

    Operating relative humidity

    (%)

    5~95

     

    size

    (")

    19×14.5×1.75

    S-Type

    19×17.9×1.75

    L-Type

     

     

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