It is well known that porous silicon can be formed by the combined chemical action of HNO3 and HF and that this reaction with silicon can be initiated by light. With n-type silicon in a diluted etching solution in the dark, the etching process can be controlled by the exposure of selected areas of the sample to light. In this work, different lasers are used to investigate the wavelength and power dependence of this etching process. It is found that the use of higher energy photons produces fluorescent porous silicon which emits light of a higher energy. It is also observed that increasing etching laser intensity also produces porous silicon which fluoresces at a higher energy. Studies to investigate the effect of etching laser intensity on the fluorescence intensity were inconclusive, suggesting that it plays a minor role compared to other environmental factors. Fluorescence micrographs show that the etched regions, though irradiated by spatially symmetric radiation, were nevertheless irregular in shape, clearly influenced by the reaction-diffusion dynamics of the chemical kinetics. As well, different regions of the etch spots clearly emitted light of different wavelengths, indicating that narrower emission profiles than are normally associated with porous silicon are possible when examined on length scales of tens of microns. Low duty cycle pulsed radiation was not effective in producing porous silicon which provides some indication about the time frame for the etching process to be photoinitiated.