With VCSEL applications being a key focus market, MPI Corporation needed a source measure unit (SMU) that was well-suited for a variety of testing applications, including VCSEL testing, LIV testing, and laser diode testing.  This case study examines how Keithley's innovative and efficient 2601B-PULSE 10 Microsecond Pulse/SMU Instrument has enabled MPI to provide ideal solutions for their customers.