We have mapped the internal pump intensity distribution of an optically pumped vertical-cavity surface-emitting laser. Spontaneous emission from quantum wells placed throughout the distributed Bragg reflectors is correlated to the pump intensity. The emission is monitored along the cleaved edge using the high spatial resolution and shallow depth of field provided by near-field scanning optical microscopy. Our results show a distinct buildup of optical intensity between the mirror stacks. Simulations performed using the transfer matrix method match well with the experimental data. ©1998 American Institute of Physics.