Abstract: This Applica TIon Brief is an outline of the detailed informa TIon that can be found in the complete version of HFDN (High Frequency Design Note) 028.0. HFDN-028.0 explains in detail how op TIcal measurements were performed, and provides guidelines for interfacing the MAX3701 blue laser driver with the blue/violet laser.


Figure 1. Op TIcal output of a blue/violet laser driven by the MAX3701.

Background and Purpose

Optical measurements of the MAX3701 driving a blue/violet laser diode were performed prior to the release of the MAX3701 in October of 2003. These measurements verified that the MAX3701 is capable of driving the blue/violet laser with rise/fall times of ≤1ns and overshoot <9% as shown in Figure 1.

This Application Brief is an outline of the detailed information that can be found in the complete version of HFDN (High Frequency Design Note) 28.0. HFDN-28.0 explains in detail how optical measurements were performed, and provides guidelines for interfacing the MAX3701 with the blue/violet laser.

The complete version of HFDN-28.0 can be obtained by request from the following link: MAX3701 datasheet.

Topics include:

Optical Evaluation Printed Circuit Board

• Materials and layout of the MAX3701 optical evaluation board
• Schematic diagram of the laser interface
• Connections and geometry of transmission lines

Optical Test Equipment

• Optical test equipment setup
• Mounting information, including thermal heat sink
• Fiber optic patch cable alignment
• Optical-to-electrical converter
• Oscilloscope-recorded waveforms of blue/violet laser driver optical output

Performance Optimization

• Parasitic elements
• Reducing overshoot and ringing on rising and falling edges
• Minimizing inductance

Decreasing the Rise/Fall Time

• Optical rise and fall times limitations
• Analysis and performance relationships