Voltage controlled power characteristics of a custom made laser diode assembly

Construction and characterization of a simple but flexible, low cost diode laser system for the excitation of carbon quantum dots as a treatment method for ocular cancers is reported. System was designed to deliver maximal amount of laser diode radiant flux to the eye of the test mice using optical cable. Detailed electronic circuit layouts of the laser diode voltage controller, supplying maximum 3 V of voltage with 20 mV resolutions, and functional description of all other components (optical cable delivery system and supporting console) are given. The system features visual signalization when the laser diode module is powered. Since the laser diode radiant flux is directly dependent on the input voltage, measurement was performed in order to obtain approximation function of this dependency. Purpose of this function is to eliminate radiant flux measurement before each experiment which requires controlled conditions.