1.1 The product overview

1550EH Series external modulation laser transmitter product is a new type of high-performance 1550nm external modulation optical transmitter. Transmitter is the 1U height, and can be easily installed in 19 “rack. 1550EH transmitter is the 1550nm dual-wavelength 7~12dBm optical output, the output signal spectral lines is narrow, more advantages in the long-distance transmission. The main devices adopt DFB low-noise, narrow linewidth, continuous-wave lasers with thermoelectric cooling device made in JDSU CATV high linearity external modulator. . Because of the international brand adoption of key components and our company system optimization control technology, SNMP network control technology, the machine’s technical performance indicators fully measure up the standard of similar imported equipment, It can provide high-quality images, digital or compressed digital signal long-distance transmission for cable television and telephone communications.

1.2 The features

1.2.1) High quality: original system optimization control technology and RF pre-distortion technology ensure that the system can acquire the maximum CTB, CSO, and SBS targets in the case of excellent performance CNR.

1.2.2) Flexibility: In ensuring the high performance system CSO, the phase modulation technology of external modulator maximize the optical power into the fiber in order to obtain long-distance transmission, and the field adjustable SBS threshold, 13,16,19, may apply a different network transmission.

1.2.3) Reliability: The 19 “1U standard rack, top-performance hot plug-in type dual power supply, it can work in the backup at 85 ∽ 265Vac City Network Voltage, MS-level automatic switching; chassis cooling automatic temperature control.

1.2.4) Intuitive: The laser is the most expensive machine components, machine equipped with microprocessor monitors the working state of the laser, the panel LCD window displays the operating parameters.

1.2.5) Network type: Select all-piece status monitoring transponder guarantee to meet the national standard and be compatible with the SCTE HMS standard, it enables network management monitoring capabilities.

 The product structure diagram

2.1 The Electrical block diagram

2.2 The transmitter’s front panel, back panel diagram

3 The main technical indicators

No. Item Units Parameter Note
1 Laser type DFB See specifications
2 Wavelength nm 1550±10 Specified before ordering
3 Optical Modulation external modulation
4 Optical output power dBm 2×10
5 SBS threshold dBm 19 13~19 dBm adj.
6 Optical Connector Optional FC/APC,SC/APC Specified before ordering
7 Frequency range MHz 47~862
8 CNR dB ≥52 GY/T143-2000
9 Flatness dB ±0.75 GY/T143-2000 6.2.4
10 RF input level dBuV 78~88 AGC automatic control
11 C/CTB dB ≥65.0 GY/T143-2000 6.2.5
12 C/CSO dB ≥65.0 GY/T143-2000 6.2.6
13 RF input impedance Ω 75
14 RF Input Return Loss dB >16(47~550)MHz



15 VCC V 90~265Vac Optional -48VDC
16 Power W ≤50 Single-supply operation
17 Working Temperature 0~50 Automatic temperature control
18 Storage temperature -20~85  
19 Working relative humidity % 20%~85%  
20 Size 19″×11″×1.75″ (W) x (D) x (H)
21 Network management interface   RJ45 supporting the browser and SNMP
Note: In the condition of stipulated link-loss, configurate 59 PAL-D analog television channel signals within 550MHz frequency, in the range of 550MHz ~ 862MHz frequency transmit digital modulation signals, digital modulation signal level ( in 8MHz bandwidth) is 10dB lower than the analog signal carrier level, when the optical input power is 0dBm, you can measure the carrier combination triple beat ratio (C / CTB), carrier combination of second-order beat ratio (C / CSO) and the carrier to noise ratio .