The patented SBSI is a small beam lateral shear interferometer that uses an air gap between glass plates to shear the beam and then projects a magnified interference fringe pattern on a camera or fluorescent viewing screen. Optical aberrations can be identified and corrected while viewing the SBSI fringe pattern in real-time. For example, coma can be corrected by changing the tilt of a collimating lens in an optical system so the fringes on the SBSI change from curved to straight. A reference line on the SBSI screen indicates the best focus (collimation) angle for the fringes. When the fringes are parallel to the SBSI reference line, all optical aberrations are minimized. Beams can be checked directly or in reflection using a rotating beam-splitter cube mounted on the front of the SBSI.

Focus alignment sensitivity is approximately 130 microradians of beam divergence, corresponding to 3° rotation of the fringes for 3½ fringes. Each SBSI is optimized for 3½ fringes for a specific wavelength and beam diameter, but every SBSI can be used to check beams over a certain
range of wavelengths and diameters.

Please inquire about special SBSI designs that are optimized for your application.

Applications

• Wavefront and collimation testing
• Test laser diodes at wavelengths from below 200nm to 1550nm.
• Test beams from 1-8mm diameter, or smaller with beam expander
• Alignment and collimation of fiber optic systems
• Optical alignment of holographic storage & disk mastering systems
• OEM integration for real-time monitoring of laser collimation

Main Features & Benefits

• Measure collimation to better than 100-200 micro radians (wavelength dependent)
• Wavelengths from 180-1700nm
• Small beam probe allows measurement between optical components.
• Simple operation reduces alignment time to minutes
• Three models to choose from including fluorescent screen, camera, and 8x zoom systems.

Intellium™ SBSI Shearing Interferometer Specifications