A novel high-speed polymeric EO modulator based on a combination of a microring resonator and an MZI

A Mach-Zehnder interferometer with an electrooptic polymer mircroring resonator adjacent to one of its branches is realized in a polymer layer stack. The microresonator is defined by reactive ion etching in the nonlinear PMMA-DR1 polymer and waveguide definition is done without etching, by using a negative photoresist (SU8) as waveguide layer. Electrooptic coefficients of 10 pm/V and modulation frequencies of 1 GHz were measured

High speed electro optic polymer micro-ring resonator

An electro-optic polymer micro-ring resonator for high speed modulation was designed, realized and characterized. The design of layer-stack and electrodes was done such that modulation frequencies up till 1 GHz should be possible. The device consists of a ridge waveguide, defined in a negative photoresist (SU8), with a poled electro-optic polymeric (PMMA-DR1) ring-resonator vertically coupled to it. The complete layerstack is sandwiched between electrodes to apply an electric field over the ringresonator in order to shift its resonance wavelength. Electro optic modulation was measured up to 50 MHz limited by weak modulation depth. Optimizing the polingprocess will increase the modulation efficiency thereby making modulation frequencies of 1 GHz measurable

High speed polymer E-O modulator consisting of a MZI with a microring resonator

A Mach-Zehnder interferometer with an polymer electro-optic micro-ring resonator on one of its branches is realized in a polymer layerstack and characterized. Electro-optic coefficients of 10 pm/V and modulation frequencies of 1 GHz were measured

Low loss, high contrast optical waveguides based on CMOS compatible LPCVD processing: technology and experimental results

A new class of integrated optical waveguide structures is presented, based on low cost CMOS compatible LPCVD processing. This technology allows for medium and high index contrast waveguides with very low channel attenuation. The geometry is basically formed by a rectangular cross-section silicon nitride (Si3N4) filled with and encapsulated by silicon dioxide (SiO2). The birefringence and minimal bend radius of the waveguide is completely controlled by the geometry of the waveguide layer structures. Experiments on typical geometries will be presented, showing excellent characteristics (channel attenuation ≤ 0.1 dB/cm, IL ≤ 1.5 dB, PDL ≤ 0.2 dB, Bg ≤ 1×10-4, bend radius « 1 mm)

Electro-optic polymers for high speed modulators

Different electro-optic polymer systems are analyzed with respect to their electro-optic activity, glass transition temperature (Tg) and photodefinable properties. The polymers tested are polysulfone (PS) and polycarbonate (PC). The electro-optic chromophore, tricyanovinylidenediphenylaminobenzene (TCVDPA),which was reported to have a highest photochemical stability [1] has been employed in the current work. Modified TCVDPA with bulky side groups has been synthesized, and a doubling of the electro-optic coefficient (r33) compared to the unmodified TCVDPA has been shown. The plasticizing effect of the chromophore, has been reduced by attaching it to the polymer backbone. SU8 (passive) and PC-TCVDPA (active) channel waveguides were fabricated by photodefinition technique and the passive waveguide losses were measured to be 5 dB/cm at 1550 nm

Conformal phased array with beam forming for airborne satellite communication

For enhanced communication on board of aircraft novel antenna systems with broadband satellite-based capabilities are required. The installation of such systems on board of aircraft requires the development of a very low-profile aircraft antenna, which can point to satellites anywhere in the upper hemisphere. To this end, phased array antennas which are conformal to the aircraft fuselage are attractive. In this paper two key aspects of conformal phased array antenna arrays are addressed: the development of a broadband Ku-band antenna and the beam synthesis for conformal array antennas. The antenna elements of the conformal array are stacked patch antennas with dual linear polarization which have sufficient bandwidth. For beam forming synthesis a method based on a truncated Singular Value Decomposition is proposed

Photodefinable electro-optic polymers for high speed modulators

We present a series of polymeric electro-optic (EO) materials based on the tricyanovinylidenediphenylaminobenzene (TCVDPA) chromophore which exhibits an exceptionally high photostability combined with a high EO activity. The EO properties of these derivatives are given and the best result was obtained with the di-tBut derivative 2, which showed a nearly doubling effect of $r_{33}$ (14 pm/V to 25 pm/V), while increasing the concentration from 25 wt% to 37.5 wt%. A microring resonator design was made based on the PC-TCVDPA system. Waveguides were fabricated by photodefinition of inverted ridges in VSC, a negative epoxy based photoresist with low refractive index

Novel ring resonator-based optical beamformer system and experimental results

A novel squint-free, continuously tunable beamformer mechanism for a phased array antenna system is proposed. It consists of filter-based optical single-sideband suppressed-carrier modulation, a fully integrated optical beam forming network using cascades of optical ring resonators as tunable delay elements, and balanced coherent optical detection. The proposed system brings advantages in optical bandwidth requirement, system complexity, and dynamic range, without introducing the problem of beam squint or limited tuning resolution. Some experimental results are presented in order to demonstrate the feasibility of the proposed concept

Broadband phased array antenna steering by means of coherent signal combining in an integrated ring resonator-based optical beamformer

A squint-free, continuously tunable optical beamformer for broadband phased array receive antennas is proposed. The complete system is demonstrated, including E/O and O/E conversions, and optical signal processing. The latter involves delay synchronization and coherent optical combining, which is performed in an integrated ring resonator-based optical beam forming network, realized in low-loss, CMOScompatible TriPleX technology. Successful combination of four beamformer input channels has been demonstrated by means of RF-to-RF measurements