<title>Optical Switches For Generation And Pulse Shaping Of Ultrashort Electrical Pulses</title>

We have compensated for gain saturation in the Nova amplifiers by producing shaped input optical pulses. A silicon switch device generates kilovolt electrical pulses for driving pockels cells. The pulse shape is easily controllable with subnanosecond resolution.

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Ultrafast pulse shaping with a traveling wave Kerr cell and picosecond rise time electrical pulses

Applied Optics ◽

10.1364/ao.18.004101 ◽

1979 ◽

Vol 18 (24) ◽

pp. 4101 ◽

Cited By ~ 8

Author(s):

Michael Stavola ◽

John A. Agostinelli ◽

Mark G. Sceats

Keyword(s):

Traveling Wave ◽

Rise Time ◽

Pulse Shaping ◽

Electrical Pulses ◽

Kerr Cell ◽

Ultrafast Pulse Shaping ◽

Ultrafast Pulse

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Generation of short electrical pulses based on bipolar transistorsny

Advances in Radio Science ◽

10.5194/ars-2-7-2004 ◽

2005 ◽

Vol 2 ◽

pp. 7-12 ◽

Cited By ~ 20

Author(s):

M. Gerding ◽

T. Musch ◽

B. Schiek

Keyword(s):

Transfer Function ◽

Output Signal ◽

Pulse Shaping ◽

Forward Bias ◽

Maximum Amplitude ◽

Pulse Generation ◽

Current Gain ◽

Pass Filter ◽

Electrical Pulses ◽

Terminal Structure

Abstract. A system for the generation of short electrical pulses based on the minority carrier charge storage and the step recovery effect of bipolar transistors is presented. Electrical pulses of about 90 ps up to 800 ps duration are generated with a maximum amplitude of approximately 7V at 50Ω. The bipolar transistor is driven into saturation and the base-collector and base-emitter junctions become forward biased. The resulting fast switch-off edge of the transistor’s output signal is the basis for the pulse generation. The fast switching of the transistor occurs as a result of the minority carriers that have been injected and stored across the base-collector junction under forward bias conditions. If the saturated transistor is suddenly reverse biased the pn-junction will appear as a low impedance until the stored charge is depleted. Then the impedance will suddenly increase to its normal high value and the flow of current through the junction will turn to zero, abruptly. A differentiation of the output signal of the transistor results in two short pulses with opposite polarities. The differentiating circuit is implemented by a transmission line network, which mainly acts as a high pass filter. Both the transistor technology (pnp or npn) and the phase of the transfer function of the differentating circuit influence the polarity of the output pulses. The pulse duration depends on the transistor parameters as well as on the transfer function of the pulse shaping network. This way of generating short electrical pulses is a new alternative for conventional comb generators based on steprecovery diodes (SRD). Due to the three-terminal structure of the transistor the isolation problem between the input and the output signal of the transistor network is drastically simplified. Furthermore the transistor is an active element in contrast to a SRD, so that its current gain can be used to minimize the power of the driving signal.

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Strategies for improved temporal response of glass-based optical switches

Scientific Reports ◽

10.1038/s41598-021-04218-3 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Matteo Calvarese ◽

Petra Paiè ◽

Francesco Ceccarelli ◽

Federico Sala ◽

Andrea Bassi ◽

...

Keyword(s):

Pulse Shaping ◽

Optical Switches ◽

Phase Shifters ◽

Temporal Response ◽

Glass Substrates ◽

Femtosecond Laser Micromachining ◽

Current State ◽

Integrated Optical ◽

Voltage Signal ◽

Thermally Actuated

AbstractWe present an optimization of the dynamics of integrated optical switches based on thermal phase shifters. These devices have been fabricated in the volume of glass substrates by femtosecond laser micromachining and are constituted by an integrated Mach–Zehnder interferometer and a superficial heater. Simulations, surface micromachining and innovative layouts allowed us to improve the temporal response of the optical switches down to a few milliseconds. In addition, taking advantage of an electrical pulse shaping approach where an optimized voltage signal is applied to the heater, we proved a switching time as low as 78 µs, about two orders of magnitude shorter with respect to the current state of the art of thermally-actuated optical switches in glass.

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