The D1861B direct-modulated laser (DML) module is a cost-effective solution for 10 Gbits/s digital transmission 12 km using traditional intracity SMF-28 single-mode fiber links. The 1310 nm wavelength eliminates the need for concern about dispersion control over most installed intracity fiber plants. The package contains a high-speed DFB laser chip, thermoelectric cooler, thermistor, optical isolator, and a rear-facet monitor photodiode, which allows for external optical power control.Features
Direct-modulated 1310 nm laser module characterized for use in 10 Gbits/s operations 12 km Average optical output power, �3 dBm typical Temperature stabilized with internal thermoelectric cooler (TEC), enabling operation within a wide temperature range +80 �C Hermetically sealed optics, isolator on TECSingle-mode fiber pigtail High relaxation frequency at low bias
Table 1. Pin Descriptions Pin No. Description Thermistor Laser Cathode dc Bias1 MPD Anode, (Negative Bias MPD) MPD Cathode Thermoelectric Cooler (+)2 Thermoelectric CoolerApplications
SR-1 SONET/SDH low-cost metro applications High-speed data communications DWDM equipment drop-side applications
1. Laser anode is case ground mAp-p drive current. 2. A positive current into this pin cools the laser. * GPO is a trademark of Gilbert Engineering Co., Inc.
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess of those given in the operational sections of the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. RF input shall be ac coupled. It is recommended that a series inductor �H be placed external to the device on Pin 3. Parameter Operating Temperature Range Storage Case Temperature Range Laser Forward Bias Pin 3, Max Positive Voltage1 Pin 3, Max Positive Current1 Reverse Voltage Photodiode TEC Current
Table 2. Electrical and Optical Characteristics (Case temperature, to +80 �C; laser temperature, 25 �C unless otherwise noted.) Parameter Average Optical Output Power Threshold Current (BOL) Wavelength Tuning Coefficient External Efficiency ac Side-mode Suppression Ratio Optical Isolation High-frequency Cutoff (3 dB) Low-frequency Cutoff (3 dB) RF Return Loss, (0.1 GHz--8 GHz) Rise/Fall Time, 10%--90% Thermoelectric Cooler Current Thermistor Resistance Thermistor Coefficient Monitor Photodiode Current Symbol PO ITH T SMSR FHIGH FLOW IS11I tR/tF ITEC RTH IMPD Condition IOP = ITH 30 mA IOP IOP2 IOP --1 IOP Min Typ 10 �4.4 Max Unit dBm mA nm nm/�C mW/A dB GHz kHz A k %/�C �A
1. 10 Gbits/s PRBS = 8.2 dB, @ IOP , TOP = 25 �C, typical 50 mAp�p drive current. 2. Measurements made with �H in series with pin 3 (laser cathode).Figure 2. Filtered Optical Eye Pattern (0 km, Fourth Order Bessel Filter, 8.2 dB ER, 20 ps/div)
LEADS 0.008" THICK x 0.030" WIDE 0.400" MIN. LENGTH 6 SPCS 0.100" (0.254) PIN 1
FIBER AND BEND LIMITER MAINTAIN FIBER BEND RADIUS GREATER THAN 1.5"