Apparatus and method for real-time optical fiber coupling

An optical fiber coupling apparatus for coupling light from an optical fiber into a light-receiving device, comprising:

• a microactuator for positioning the end of said fiber with respect to said light-receiving device, and
• a control circuit comprising
• a reference light source for emitting a reference light signal with an essentially constant intensity and
• incoupling means for coupling said reference light signal into the core of said fiber,
• said control circuit having a controlled variable and a manipulated variable determined from said cotrolled variable, wherein
• said controlled variable is the intensity of said reference light signal coupled into the fiber core and detected by said light-receiving device and
• said manipulated variable is a position of the fiber end positioned by said microactuator.

A method for coupling light from a light-emitting device into an optical fiber, comprising the steps of:

• positioning the end of said fiber with respect to said light-emitting device;
• incoupling light from said light-emitting device into the core of said fiber, so that light propagates through the core of said fiber;
• coupling out of the fiber a well-defined portion of the light propagating through the core of said fiber;
• detecting the intensity of said light portion;
• and
• performing a control operation, wherein
• said detected light intensity is used as the controlled variable from which the manipulated variable is determined in said control operation and
• the position of the fiber end is used as the manipulated variable in said control operation.

A method for coupling light from an optical fiber into a light-receiving device, comprising the steps of:

• positioning the end of said fiber with respect to said light-receiving device;
• incoupling a reference light signal with an essentially constant intensity into the core of said fiber, so that a portion of said reference light signal propagates through the core of said fiber;
• detecting the intensity of said light portion in said light-receiving device;
• and
• performing a control operation, wherein
• said detected light intensity is used as the controlled variable from which the manipulated variable is determined in said control operation and
• the position of the fiber end is used as the manipulated variable in said control operation.