Laser power monitoring with lens sampling device

A laser apparatus with power monitoring, comprising:

• a laser source to generate a laser beam;
• a photodetector to monitor a power of the laser beam;
• a transmissive sampling device including one or more lenses positioned in a beam path of the laser beam, the one or more lenses including a partially reflective surface to generate and focus a partial reflection of the laser beam, the partially reflective surface being either (a) a concave surface facing the laser beam as incident on the transmissive sampling device or (b) a convex surface facing away from the laser beam as incident on the transmissive sampling device, the partially reflective surface being oriented to direct the partial reflection away from the beam path and onto a propagation path to the photodetector, the one or more lenses imposing a non-zero net-optical power on the laser beam transmitted along the beam path, the non-zero net-optical power being at least 10 diopters in magnitude;
• and
• a focusing element disposed in the beam path after, and adjacent, the transmissive sampling device to modify focusing properties of the laser beam.