A photonic analog-to-digital converter based on an unbalanced Mach-Zehnder quantizer

Abstract

A Mach-Zehnder modulator (MZM) based analog to digital converter (ADC) is described. The signal to be digitized is applied to a single electrode of a high speed unbalanced modulator that acts as a quantizer. The rest of the system consists of commercially available wavelength division multiplexing (WDM) components. Analysis indicates that 6 bit operation at 40 Giga Samples per second (GS/s) is possible with moderate optical carrier power.

Resolution-enhanced all-optical analog-to-digital converter employing cascade optical quantization operation

“…Extensive optical quantization schemes have been proposed and improved aiming to achieve high quantization resolution, e.g. the phase quantization by the modulation and interference [7][8][9][10][11][12][13][14][15] and the frequency quantization by the nonlinear effects in highly nonlinear fibers [16][17][18][19][20][21]. In these schemes, the cascade quantization methods demonstrated in [12] and [13] have great advantages compared to the other schemes because the enhancement of more than 1-bit in the quantization resolution can be obtained on the basis of the conventional phase quantization schemes.…”

“…The UMZM consists of two Y-junctions, two transmission arms with different geometric path lengths, electrodes, and LiNbO 3 substrate. In consideration of the TE mode input, the power transfer function of the UMZM can be obtained as [9,22] ( )…”

Proposal for an all optical analog-to-digital converter based on modal birefringence in a polarization maintaining fiber

“…In PSOQ, the key issue is how to obtain the desired phase shift precisely to ensure the effective number of bits (ENOB). Though some feasible approaches have been presented, such as a fiber squeezer, 11 multi-wavelength phase shift in LiNbO 3 phase modulator, 12 unbalanced Mach-Zehnder modulator, 13 and electrically controllable phase shifter, 14 these approaches either need additional mechanical adjustment 11,14 or the configuration is not flexible and the requirement of the device is strict, 12,13 which leads to the realization of the PSOQ's complication.…”

Multimode interference coupler based photonic analog-to-digital conversion scheme

“…Photonic ADC emerges as an alternative choice. During the past decades, researchers have proposed many smart approaches to bring photonic technologies to the field of high-speed ADCs [1][2][3][4][5]. The most well-known examples are the scheme proposed by Taylor in 1979 [1], and the phase-shifted optical quantization scheme proposed by Stigwall in 2005 [2].…”

“…The most well-known examples are the scheme proposed by Taylor in 1979 [1], and the phase-shifted optical quantization scheme proposed by Stigwall in 2005 [2]. Much work has been carried out to implement and improve the two schemes [3][4][5]. The approaches, which follow Taylor's idea, suffer from the drawbacks that either one modulator per bit or distribution of the high analog signal applied to many electrodes [1].…”