Fiber-based probe for electrooptic sampling

Recent Advances in the Design of Electro-Optic Sensors for Minimally Destructive Microwave Field Probing

“…In practical respects, the reflective scheme is generally preferred, with a sensor tip as the terminal of the optical sensor and the light being modulated at the sensor terminal when it is exposed to an electric field. The reflected beams to be detected are efficiently returned from the sensor using a number of common methods: a mirror [ 7 – 9 , 13 – 15 ]; total internal reflection [ 11 – 13 ]; highly reflective surfaces from the device under tests [ 16 ]; or through fabrication of a resonator on the sensor plate [ 10 ].…”

Electro-optic probing of microwave fields using a wavelength-tunable modulation depth

“…While the resonant-reflection probe had its maximum EO-modulation response at a low reflected intensity (bottom curves in figure 3), a conventional, doublepass configuration reflects a high intensity from an HR coating on the exposed face of a probe. In the latter, a GRIN lens would be used for collimating or focusing the probe beam into a relatively thick crystal [8,9], while in the former, a thin crystal was mounted directly on the fiber facet (as in [7,9,10]). In the non-resonant configurations, the quarter waveplate/analyzer polarization components would be required, and typically 50% of the input probe light delivered to the detector, about five times more than for the resonant probe.…”

“…In addition to a sensitivity enhancement, the all-fiber configuration of figure 4 provides an improved spatial resolution and scanning mobility for field mapping compared to free-space measurement systems. This is due to the small optical mode-field diameter and the flexibility realized by mounting the electro-optic field sensor at the end of an optical fiber [7][8][9][10]. Despite these advantages, most high-frequency EOP systems have required either expensive pulsed lasers [3,8,9,12,13,19] or cw lasers coupled with fast photodetectors [7,17] for their operation.…”

“…The poor maneuverability and opto-mechanical robustness of the free-space EO sensor have been improved upon in several cases through the use of a reflective, fiberbased probe geometry [7][8][9][10]. Furthermore, the compactness and reliability of such a fiber-based embodiment provide for enhanced spatial resolution and relief from the necessity of tedious optical alignment.…”

Spatial scanning-probe array system for silicon-on-insulator integrated circuits

“…In [6], electrooptic sampling for the GaAs integrated circuits and use of the intensity modulation are presented. In [7], AlGaAs is fabricated on single fiber tip. The resonance between DUT and fiber is used for the measurement.…”