Data Sheet 2.5Gb/s Buried Het Laser 360km Extended Reach With Optional Etalon Stabilization LC25W-B (360km) This laser module employs the Bookham strained layer MQW Buried Heterostructure DFB laser chip, and has been designed specifically for use in Wavelength Division Multiplexed (WDM) 2.5Gb/s long distance optical fiber trunk systems. The device is packaged in a hermetically sealed 14-pin butterfly package incorporating an isolator and monitor photodiode for control of the power of the laser over life and all operating conditions. The device is available with a number of power options depending on application and link span requirements. The optional internal Etalon wavelength stabilization and low chirp performance makes this product compliant with 50GHz optical channel spacing. Features: • 2.5Gb/s operation • +/-95pm wavelength stability over life without Etalon locker • Optional Etalon wavelength stabilization provides 50GHz optical channel spacing compliance for interlay or future upgrade • Narrow spectral line-width • Internal TEC with precision NTC thermistor for temperature control • Entire C & L-band ITU avelengths available (1527nm to 1605nm) • Code reduction with single product for reaches up to 360km • GaInAsP SLMQW DFB single frequency laser chip • InGaAs monitor photo-diode • Hermetically sealed 14-pin butterfly package with optical isolator • RoHS compliant Applications: • WDM • On-off ramps • Long-Haul • DWDM on ITU Grid 1 Data Sheet Parameters Conditions Parameter Min Threshold current (Ith) Slope efficiency by product 2 3 4 7 RF input reflection coef (S11) mW mW mW mW Typ Max Unit 10 22 mA 0.04 0.06 0.08 0.143 0.09 0.13 0.17 0.43  Forward voltage 1.3 Peak wavelength (λp)  Dispersion penalty at 360 km  Time averaged spectral linewidth 1527 -20 dB 0.1 Side-mode suppression 32 Optical rise/fall time Unlocked Etalon locked 50 40 250 250 Monitor dark current Thermistor resistance dB 1.8 V 1605 nm 2 dB 0.6 nm 40  Monitor photo current -10 dB 125 ps 1200 360 µA 100 nA 10 Heatpump current 70°C case temperature Heatpump voltage 600 900 mA 70°C case temperature 1.0 2.4 V 15°C to 35°C 0.09 Change of λp with laser temp. Change in λ over life and operating conditions Optical Spectral Window Unlocked  Locked, over life & temperature including chirp  250 kΩ nm/°C -45 +145 pm -9 +9 GHz  50 Ω measurement system, f = dc - 3GHz.  Submount temperature between 20°C to 35°C start of life to achieve required λp. For the 10mW version, submount temperature is between 15°C to 35°C start of life.  Standard product dispersion penalty will be compliant to the specified link length of 360km using an extinction ratio of 10dB. Fiber dispersion characteristics are derived from the following equation. So D ( )= ( 4 4 0 3 ) ps /(nm.km) Where So =0.092 ps/(nm2.km) and λ = 1302nm.  Measurements determined from 20 - 80% pk - pk.  For more information on wavelength control and drift over life refer to applications note DR1670. To give symmetrical wavelength performance about the ITU channel wavelength (+/-95pm) offset the laser wavelength by –50pm at start of life set up. 2 Data Sheet Absolute Maximum Ratings Parameter Min Max Unit 0 70 °C 20 35 °C -40 85 °C Laser current above Ith 100 mA Laser reverse voltage 1.0 V Laser reverse current 10 µA Monitor diode bias -10 V Heatpump voltage 2.4 V Case operating temperature Laser submount operating temperature Storage temperature Fiber bend radius   30 mm Notes:  Product without locker can be tuned onto the next 100 GHz ITU channel in the red shift direction (2x100 GHz tunability) by increasing the submount temperature to a maximum of 43°C.  For the 10mW version, the minimum laser submount operating temperature is 15°C. Reliability/Quality Meets qualification requirements of Telcordia / Bellcore GR468-Core for central office environment. Operating reliability <500 FITs1 in 15 years. 1- Assumes laser die submount held at <35°C by internal thermoelectric cooler, mean forward current of 35 mA, and end of life limits based on 10 mA increase in Ith and 25% change in laser efficiency. FIT rate data for other end of life criteria, including minimum extinction ratio requirements, are available upon request. Outline Drawing Dimensions (mm) Figure 1: Outline Drawing Note: 3 Devices can be supplied with the leads trimmed to a length of 3.81mm. Please see Ordering Information section. Fiber length: 1130mm to 1190mm. Data Sheet Instructions for use – LC25W****B/LC25EW****B Pin 1 and Pin 2 Thermistor Pin 6 TEC (+), Pin 7 TEC (-) The thermistor is used in a control loop in conjunction with the thermo-electric cooler to maintain the laser submount temperature at the required value for wavelength. Operating current should be less than 100µA to prevent self-heating errors. Applying a positive voltage on pin 6 with respect to pin 7 will cause the internal submount to be cooled relative to the case temperature. Reversing the polarity will raise the submount temperature relative to the case. The TEC supply should be capable of delivering up to 0.9A at 2.4V. For Etalon stabilized devices the thermistor is used for the initial set up of the submount temperature at the required wavelength value. Operating current should be less than 100 µA to prevent self-heating errors. Once the initial submount temperature has been achieved control of the TEC current is handed over to the Etalon locking circuit to achieve fine tuning. Pin 8, 9, 11, 13 Case ground Pin 3 Laser DC bias (-) Laser bias current (negative with respect to package ground) is applied via this pin which forms one side of the bias-T connection to the laser cathode. Pin 4 Monitor anodes, Pin 5 Common Monitor cathode The back facet monitor provides a mean power reference for the laser and is normally operated with a 5V reverse bias. For Etalon stabilized devices the monitor diodes are arranged in the package such that they give an equal monitor current when the laser wavelength is matched to the ITU grid. A reverse bias must be applied equally across each of the monitors, this is commonly achieved by applying 5 V to Pin 5. 4 These pins must be grounded in all applications. Pin 10 This pin is not connected for the LC25W product and it should be grounded if possible. For the Etalon locked product this pin is used for the monitor long anode. The monitor diodes are arranged such that they give an equal monitor current when the laser wavelength is matched to the ITU grid. A reverse bias must be applied equally across each of the monitors, this is commonly achieved by applying 5V to pin 5. Pin 12 Laser modulation (-) The data input (modulation current) is applied via this pin which is a nominal 25 Ohm impedance coplanar line. Pin 14 N/C This pin is not connected. It should be grounded if possible. Data Sheet Connections Without Etalon Pin Function Pin Function 1 Thermistor 1 Thermistor 2 Thermistor 2 Thermistor 3 Laser DC bias (-) 3 Laser DC bias (-) 4 Monitor Anode (-) 4 Monitor Short Anode (-) 5 Monitor Cathode (+) 5 Monitor Cathode (+) 6 TEC (+) 6 TEC (+) 7 TEC (-) 7 TEC (-) 8 Case Ground 8 Case Ground 9 Case Ground 9 Case Ground 10 Not Connected 10 Monitor Long Anode (-) 11 Case Ground 11 Case Ground 12 Laser Modulation (-) 12 Laser Modulation (-) 13 Case Ground 13 Case Ground 14 Not Connected 14 Not Connected Safety Information Laser safety classifications: IEC 60825-1:Edition 1.2 Class 1M 21 CFR Ch.1 (4-1-97 Edition) Class IIIb Electrostatic discharge: ESD threshold >500V TA-TSY-000870 class 3. 5 With Etalon Data Sheet RoHS Compliance Bookham is fully committed to environment protection and sustainable development and has set in place a comprehensive program for removing polluting and hazardous substances from all of its products. The relevant evidence of RoHS compliance is held as part of our controlled documentation for each of our compliant products. RoHS compliance parts are available to order, please refer to the ordering information section for further details. Ordering Information: LC25 [Etalon Option] [Wavelength] [Power Option] [Reach] [Connector] W = none EW = Etalon **** E = 2 mWpk C = 3 mWpk A = 4 mWpk B = 7 mWpk B = 360km - J28 = SC/PC J34 = FC/PC J57 = LC J59 = MU **** = Last four digits of wavelength value E.g. for lp = 1545.32nm **** = 4532 Product without locker can be tuned onto the next 100GHz ITU channel in the red shift direction (2x100GHz tunability) i.e. an LC25W4135CB-J28 can be tuned to service the 1542.14nm ITU channel. Other connector types are available on request. E.g. LC25W4532BB-J28 is a 7mW 1545.32 nm device with an SC connector for use in a 360km application. E.g. LC25EW4532EB-J28 is a 2mW 1545.32 nm device with an SC connector for use in a 360km application with optional Etalon stabilization. Trimmed lead option Devices can be supplied with the leads trimmed to a length of 3.81mm typ. This option can be specified by adding a ‘K’ suffix after the reach option. E.g. LC25W4532BAK-J28 is a 10mW 1545.32nm device with an SC connector and a lead length of 3.81mm typical, for use in a 175km application. Contact Information North America Bookham Worldwide Headquarters Europe Paignton Office Asia Shenzhen Office 2584 Junction Ave. San Jose CA 95134 USA Brixham Road Paignton Devon TQ4 7BE United Kingdom 2 Phoenix Road Futian Free Trade Zone Shenzhen 518038 China • Tel: +1 408 919 1500 • Tel: +44 (0) 1803 66 2000 • Fax: +1 408 919 6083 • Fax: +44 (0) 1803 66 2801 • Fax: +86 755 33305805 +86 755 33305807 • Tel: +86 755 33305888 Important Notice Performance figures, data and any illustrative material provided in this data sheet are typical and must be specifically confirmed in writing by Bookham before they become applicable to any particular order or contract. In accordance with the Bookham policy of continuous improvement specifications may change without notice. The publication of information in this data sheet does not imply freedom from patent or other protective rights of Bookham or others. Further details are available from any Bookham sales representative. www.bookham.com email@example.com DANGER INVISIBLE LASER RADIATION DO NOT VIEW DIRECTLY WITH OPTICAL INSTRUMENTS CLASS 1M LASER REFERENCE IEC 60825-1: Edition 1.2 6 INVISIBLE LASER RADIATION AVOID DIRECT EXPOSURE TO BEAM OUTPUT POWER 21mW WAVELENGTH >1510nm CLASS IIIb LASER PRODUCT THIS PRODUCT COMPLIES WITH 21 CFR 1040.10 ISO14001:1996 EMS 504193 TL9000 Rev 3.0 (ISO9001:2000) FM15040 Caution - use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. BH13087 Rev 1.0 January 2007. ©Bookham 2006. Bookham is a registered trademark of Bookham Inc.