A catheter comprises an elongated catheter body, a control handle, and a hollow tip electrode having a radially-symmetrical shell defining a cavity surrounding a center inner location from which light is emitted to pass through a plurality of openings formed in the shell for interaction with tissue and/or fluid, such as blood, outside of and in contact with the shell. Light interacting with tissue is reflected back into the cavity for collection whereas light interacting with fluid, such as blood, is absorbed. By analyzing the light collected in the cavity, a determination is made as to a ratio of light reflected by tissue versus light absorbed by fluid for indicating the amount of contact between the tip electrode and tissue. Alternatively, fluorescence may similarly be employed (light is emitted at one wavelength and detected at one or more different wavelengths) since tissue and blood have different fluorescence properties at various wavelengths. An integrated ablation and spectroscopy system further comprises an RF generator, a light source and a light analyzer adapted to analyze the light collected in the cavity.