Abstract: There is provided a Raman signal detection including a laser emitter and an optical element. The optical element includes an optical element body, an emitter face with a short pass optical coating, a Raman signal face with a long pass optical coating and a sample face. The optical element is positioned with a laser emitter output beam incident upon the emitter face. The emitter face receives the laser emitter output beam and transmits an emitter face output beam through the optical element body and the sample face to emit a sample face output beam. The sample face receives and transmits a sample reflection beam generated from the sample face output beam to the emitter face. The emitter face reflects and transmits the sample reflection beam the sample reflection beam through the Raman signal face to emit a Raman signal output beam to a Raman signal detector.

Abstract: There is provided a laser apparatus that includes a laser emitter configured to emit a laser emitter output beam. The apparatus includes a transmissive grating positioned with the laser emitter output beam incident upon the grating. The grating transmits a first order output beam. The apparatus includes a feedback element positioned with the first order emitted beam incident upon the feedback element. The feedback element returns a feedback element return beam incident upon the grating. The feedback element transmits a feedback element output beam at a feedback element output beam width. The laser apparatus includes a pin-hole element with a pin-hole positioned with the feedback element output beam incident upon the pin-hole. The feedback element output beam width is not greater than the pin-hole width. The pin-hole element transmits a pin-hole output beam at a pin-hole element output beam width less than the feedback element output beam width.

Abstract: There is provided a Raman signal detection including a laser emitter and an optical element. The optical element includes an optical element body, an emitter face with a short pass optical coating, a Raman signal face with a long pass optical coating and a sample face. The optical element is positioned with a laser emitter output beam incident upon the emitter face. The emitter face receives the laser emitter output beam and transmits an emitter face output beam through the optical element body and the sample face to emit a sample face output beam. The sample face receives and transmits a sample reflection beam generated from the sample face output beam to the emitter face. The emitter face reflects and transmits the sample reflection beam the sample reflection beam through the Raman signal face to emit a Raman signal output beam to a Raman signal detector.