In today’s world, optical waveguides are a fundamental component to the telecommunications industry. Station Gamma is an automated motion, waveguide loss measurement system that includes multiple excitation sources and detector capability from the UV to the near IR.


*        ISA triax .32 m focal length


*        PMT (UV-Vis)

*        InGaAs (Vis-near IR) TE cooled


*        1.5 mm

*        1.3 mm

*        980 nm

*        633 nm

Stanford Research lock-in and chopper

*        SR 830 DSP Lock-in

*        SR 504 optical chopper


*        Motions

·        Newport ESP 300

·        100 mm 1-axis motion mm resolution

*        Melles Groit manipulators

·        4 axis waveguide manipulator         

·        3 axis manual position stage


*        IEEE 488

*        LabVIEW

·        Integrated movement, detection and data acquisition by LabVIEW programming

Gamma Scientific microscope and optical fiber pickup.

*        1250 mm dia. fiber pickup in optical axis of microscope

*        Bundle fiber output to spectrometer and detectors

                              *        Tube camera – responsive to beyond 1.7 mm for visual

                                         inspection of IR guides.


A typical measurement:

Polarized focused light is end face coupled into a waveguide.  The guide rests on a 3-axis manual position stage and is viewed from above.    The camera is mounted onto a microscope system with an inline fiber optic pickup.  The microscope system captures outscatered light from the top of the waveguide and records the intensity of the captured light as the camera system moves the length of the guide. The camera microscope system is mounted on a linear motion stage accurate to < 1mm.  The position and light intensity are automatically recorded and used to calculate the loss of that guide. Weak light signals are isolated and amplified with respect to the background by an optical chopper and lock in amplifier system.

 Bob(H) is doing measurement on Gamma-Station