High-bandwidth Photodiode Research Articles

Plasmonic Resonance-Enhanced Low Dark Current and High-Speed InP/InGaAs Uni-Traveling-Carrier Photodiode

High-speed and high-efficiency photodiodes are especially beneficial for exponential data communication traffic growth. However, improving high responsivity while maintaining low dark current and high bandwidth remains a challenge for vertical detector design. This study proposes a plasmonic InP/InGaAs uni-traveling-carrier photodiode with optical antenna arrays, which exhibits a low dark current of 2.52 nA at a −3 V bias voltage, a high bandwidth of over 40 GHz, and a high responsivity of 0.12 A/W. The absorption efficiency of the photodiode shows 2-fold improvement using plasmonic resonance generated by nanodisks at 1550 nm. This work designs a low dark current and high-bandwidth photodiode with improved responsivity, which provides a potential method for high-speed vertical photodiode design.

Single-shot high-resolution characterization of optical pulses by spectral phase diversity.

The concept of spectral phase diversity is proposed and applied to the temporal characterization of optical pulses. The experimental trace is composed of the measured power of a plurality of ancillary optical pulses derived from the pulse under test by adding known amounts of chromatic dispersion. The spectral phase of the pulse under test is retrieved by minimizing the error between the experimental trace and a trace calculated using the known optical spectrum and diagnostic parameters. An assembly composed of splitters and dispersive delay fibers has been used to generate 64 ancillary pulses whose instantaneous power can be detected in a single shot with a high-bandwidth photodiode and oscilloscope. The diagnostic is experimentally shown to accurately characterize pulses from a chirped-pulse-amplification system when its stretcher is detuned from the position for optimal recompression. Pulse-shape reconstruction for pulses shorter than the photodetection impulse response has been demonstrated. Various investigations of the performance with respect to the number of ancillary pulses and the range of chromatic dispersion generated in the diagnostic are presented.

Phase Measurement of a Microwave Optical Modulation: Characterisation and Reduction of Amplitude-to-Phase Conversion in 1.5 μm High Bandwidth Photodiodes

High accuracy and low noise measurement of the phase of a microwave signal requires that spurious contributions are adequately dealt with. In this paper we investigate the power-to-phase coupling in two commercial high bandwidth P-I-N, near-IR photodetectors. We observe that a sudden change of the optical power induces a transient of the phase of the 20 GHz signal, at different time scales. The temperature rise of the photodetector junction is likely to be involved in this dynamical behaviour. The value of the bias voltage applied to the photodetector appears to control the size of the phase transients, as well as the optical power for which the slope of the amplitude-to-phase coupling cancels. The most efficient way to reduce amplitude to phase couplings consists in implementing optical demodulation, instead of electrical demodulation, of the microwave signal.

Experimental Demonstration of Photonic Millimeter-Wave System for High Capacity Point-to-Point Wireless Communications

We present experimental results of 10 Gb/s wireless communications over a distance of 520 meters in the W-band. The transmitter makes use of photonic upconversion with a high bandwidth photodiode to allow for minimum hardware at the antenna. We present results with two receiver configurations. The first uses all electronic methods with a balanced Schottky diode mixer for downconversion, and the second uses photonics to limit the hardware at the receive antenna by photonically generating the local oscillator drive signal and transporting the intermediate frequency signal over a microwave photonic link.

A frequency-stabilized Yb:KYW femtosecond laser frequency comb and its application to low-phase-noise microwave generation

We present an optically stabilized Yb:KYW fs- laser frequency comb. We use an f-2f nonlinear interfer- ometer to measure the carrier envelope offset frequency (f0) and the heterodyne beatnote between the comb and a stable CW laser at 1068 nm to detect fluctuations in the comb repetition rate (frep). Both of these degrees of free- dom of the comb are then controlled using phase-locked loops. As a demonstration of the frequency-stabilized comb, we generate low-phase-noise 10 GHz microwaves through detection of the pulse train on a high bandwidth photodiode. The phase noise of the resulting 10 GHz microwaves was -99 dBc/Hz at 1 Hz and the corre- sponding Allen deviation was \2.6 9 10 -15 at 1 s, mea-

Versatile wideband balanced detector for quantum optical homodyne tomography

We present a comprehensive theory and an easy to follow method for the design and construction of a wideband homodyne detector for time-domain quantum measurements. We show how one can evaluate the performance of a detector in a specific time-domain experiment based on the electronic spectral characteristic of that detector. We then present and characterize a high-performance detector constructed using inexpensive, commercially available components such as low-noise high-speed operational amplifiers and high-bandwidth photodiodes. Our detector shows linear behavior up to a level of over 13dB clearance between shot noise and electronic noise, in the range from DC to 100MHz. The detector can be used for measuring quantum optical field quadratures both in the continuous-wave and pulsed regimes with standard commercial mode-locked lasers.

Photonic integration using asymmetric twin-waveguide (ATG) technology: part I-concepts and theory

In this first of two papers (hereinafter called Paper I), we present a universal approach for simply realizing monolithic photonic integration based on asymmetric twin-waveguide (ATG) technology. The concepts and important developments leading to ATG integration technology will be reviewed. The ATG structure consists of active and/or passive devices formed in separate, vertically displaced waveguides. Light is transferred between the waveguides via very low loss, lateral, adiabatic tapered mode transformers, allowing different optical functions to be realized in the different waveguides. The design of the adiabatic tapered mode transformer uses an algorithm based on perturbation theory. We show that the same designs can also be deduced from coupled local mode theory. Using the perturbation algorithm to design the taper coupler in an ATG based high bandwidth photodiode, a transfer efficiency of greater than 90% from the fiber waveguide to the coupling waveguide is achieved while the taper length can be reduced by 35% compared to conventional two-section linear taper couplers. The taper design algorithm is further optimized to make the adiabatic taper couplers tolerant to variations in incident light polarization, operation wavelength, and dimensional control during fabrication. Finally, we propose and design a taper that adiabatically couples light from the fundamental mode to the first-order mode. Such a taper coupler is useful in an integrated semiconductor optical amplifier/p-i-n detector circuit.