A flow cell module for use in a liquid sample analyzer includes a module housing, a liquid core waveguide mounted in the module housing to receive a flow of a liquid sample from a liquid sample source, an input optical fiber disposed in the module housing to transmit radiation from a radiation source to the liquid core waveguide, an input termination located on an input end of the input optical fiber, a first kinematic connection mechanism operative to bias the input termination in a first direction along a first axis while permitting displacement of the input termination in a first opposing direction along the first axis, and a second kinematic connection mechanism operative to bias the input termination in a second direction along a second axis while permitting displacement of the input termination in a second opposing direction along the second axis. The second axis is transverse to the first axis.