Patent ID: 7729392

Claim:
An optically pumped laser apparatus, comprising: a substrate disposed along an axis; a first mirror adapted to reflect light at a first wavelength and disposed perpendicularly to the axis; a gain medium adapted to receive an external light, the external light comprising a set of wavelengths which excites the gain medium, the gain medium adapted to lase and polarize the light at the first wavelength, the gain medium disposed along the axis; a Q-switch adapted to attenuate and transmit light at the first wavelength, the Q-switch disposed along the axis; an HR/HT mirror adapted to pass light at the first wavelength and reflect a light at a second wavelength, the HR/HT mirror disposed perpendicularly to the axis; an OPO rod adapted to convert a portion of the light at the first wavelength into the light at the second wavelength, the OPO rod disposed along the axis; and an output coupler (OC) disposed perpendicularly to the axis and adapted to reflect the light at the first wavelength and pass a portion of the light at the second wavelength so as to provide an output, the light at the first wavelength reflecting between the first mirror and the OC and though the gain medium and the Q-switch and the light at the second wavelength reflecting between the HR/HT mirror and the OC and through the OPO rod, where the substrate has a film thereon disposed between the substrate and the gain medium, the film adapted to reflect at least some of the external light towards the gain medium so as to provide an additional amount of energy, where the film has a film thermal expansion coefficient (TCE) and the substrate has a substrate TCE, the film TCE and the substrate TCE having no substantial difference therebetween so that the film adheres to the substrate over a wide range of temperatures while the output comprises the additional amount of energy.