Perhaps you should try some spelling variations:
"optic sensorss" » "optic sensors", "optic sensor", "optics sensors"
"optical sensors" » "optical sensings", "optic sensorss"
"optical sensor" » "optical sensing", "optic sensors"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("optical sensors") OR ("optic sensorss"))) OR ("optical sensor")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"optical sensors\") OR (\"optic sensorss\"))) or (\"optical sensor\"))".
• Removing quotes may allow a broader search: (((( optical sensors ) OR ( optic sensorss ))) or ( optical sensor )).
• Adding a wildcard symbol may retrieve word variants: (((("optical sensors") OR ("optic sensorss"))) or ("optical sensor"))*.