Micro-structured integrated electro-optic LiNbO 3 modulators (original) (raw)

Waveguide electro-optic modulation in micro-engineered LiNbO 3

Journal of Optics A: Pure and Applied Optics, 2008

In this paper, after describing the basics of LiNbO 3 based integrated electro-optic modulators, we will show how techniques such as etching, domain inversion and thin film processing can be used to realize new geometries which can take the performance to unprecedented levels. In particular we will review recent results on the use of domain inversion on a micron scale to improve the electro-optic response of LiNbO 3 waveguide modulators in terms of bandwidth and driving voltage. These applications of domain inversion techniques might be even more important and commercially valuable than those in nonlinear optics (e.g. quasi-phase-matched optical parametric devices). With respect to standard single-domain structures, larger bandwidths and lower driving voltages can be obtained, thus achieving figure of merits for the electro-optic response that are up to 50% larger. As a demonstration, a chirp-free modulator, having ∼2 V switching voltage and bandwidth of 15 GHz, was fabricated by placing the waveguide arms of a Mach-Zehnder interferometer in opposite domain oriented regions. The modulator, as indicated by system measurements, could be driven in a single-drive configuration with inexpensive low-voltage drivers, e.g. SiGe based, typically used for electro-absorption devices.

Integrated electro-optic modulators in micro-structured LiNbO3

2008

We review recent advances in micro-structuring LiNbO3 crystals and demonstrate the achievement of large bandwidths and lower driving voltages using domain inversion. We will report on a domain engineered Mach-Zehnder modulator for 10Gb/s transmission with ∼2V switching voltage driven by inexpensive Si-Ge drivers.

Integrated electro-optic modulators in micro-structured

2008

We review recent advances in micro-structuring LiNbO3 crystals and demon- strate the achievement of large bandwidths and lower driving voltages using domain in- version. We will report on a domain engineered Mach-Zehnder modulator for 10Gb/s transmission with ∼2V switching voltage driven by inexpensive Si-Ge drivers.

Very low voltage single drive domain inverted LiNbO_3 integrated electro-optic modulator

Optics Express, 2007

Domain inversion is used in a simple fashion to improve significantly the performance of a waveguide electro-optic modulator in z-cut LiNbO 3. The waveguide arms of the Mach-Zehnder interferometer are placed in opposite domain-oriented regions under the same, narrower and more efficient electrode, so that opposite phase shifts (push-pull effect) can still be achieved despite the arms being subjected to the same electric field. Switching voltages close to 2 V are obtained, which allow 10Gb/s modulation with inexpensive drivers, such as those used for electro-absorption modulators, which deliver driving voltages well below 3V.

Thin Film Lithium Niobate Electro-Optic Modulator for 1064 nm Wavelength

IEEE Photonics Technology Letters, 2021

We present a thin film crystal ion sliced (CIS) LiNbO 3 phase modulator that demonstrates an unprecedented measured electro-optic (EO) response up to 500 GHz. Shallow rib waveguides are utilized for guiding a single transverse electric (TE) optical mode, and Au coplanar waveguides (CPWs) support the modulating radio frequency (RF) mode. Precise index matching between the co-propagating RF and optical modes is responsible for the device's broadband response, which is estimated to extend even beyond 500 GHz. Matching the velocities of these co-propagating RF and optical modes is realized by cladding the modulator's interaction region in a thin UV15 polymer layer, which increases the RF modal index. The fabricated modulator possesses a tightly confined optical mode, which lends itself to a strong interaction between the modulating RF field and the guided optical carrier; resulting in a measured DC half-wave voltage of 3.8 V•cm −1. The design, fabrication, and characterization of our broadband modulator is presented in this work.

Micro-nano structured electro-optic devices in linbo3 for communication and sensing

2012

A material that is enabling integrated optics is the ferroelectric crystal Lithium Niobate (LiNbO3), which has excellent electro-optical, acousto-optical and nonlinear optical properties. Moreover, it can be doped with laser-active ions and allows for simple fabrication of low-loss optical waveguides. The broad aim of this work is to develop and introduce advanced micro- and nano-fabrication techniques for LiNbO3 and a new class of integrated based telecommunication and sensing devices. The techniques developed include precise micro-domain inversion, etching, bonding and thin film fabrication. From a device point of view, domain inversion is used to improve the electro-optic response of LiNbO3 waveguide modulators in terms of bandwidth and driving voltage. With respect to standard single-domain structures, larger bandwidths and lower driving voltages can be obtained, thus achieving figure of merits for the electro-optic response that are up to 50% larger. As a demonstration, a chirp...

Thin layer design of X-cut LiNbO3 modulators

IEEE Photonics Technology Letters, 2000

Microwave-optical velocity matching and 50 impedance matching are difficult to achieve with LiNbO 3 traveling wave modulators. We perform a detailed study (simulations) of the microwave and optical performance characteristics for modulators using thin layer (few micrometers), X-cut LiNbO 3 and find significant improvements in velocity and impedance matching together with a lower .

LiNbO3 Mach-Zehnder modulator with chirp adjusted by ferroelectric domain inversion

IEEE Photonics Technology Letters, 2002

Domain inversion under coplanar waveguide electrodes is proposed to improve the frequency-chirping behavior of z-cut LiNbO 3 Mach-Zehnder modulators. This is achieved by introducing phase reversal electrode section in tandem with inverted ferroelectric domain section. The resulting chirp is shown to be related to the length of the inverted domain. The method opens the way to single-drive modulators with predetermined chirp parameter. The fabrication of such modulators is described, and experimental results confirm that the-chirp parameter can be more than ten times smaller than that of a conventional Z-cut device.