Femtosecond laser has been widely used in materials micro-processing when high accuracy and small structure size are required. When a transparent material like glass is irradiated by a tightly focused femtosecond laser, the photoinduced reaction is expected to occur only near the focused part of the laser beam due to the multiphoton processes. We observed various induced structures e.g. color center defects, refractive index change, micro-void and micro-crack, in glasses after the femtosecond laser irradiation. Here, we demonstrate the fabrication of various micro-optical components, e.g. optical waveguide, microgating, microlens, fiber attenuator, 3-dimensional optical memory by using the femtosecond laser-induced structures. The femtosecond laser direct writing technique is very promising in the fabrication of micro-optical components with various optical functions.

The large refractive index contrast between silicon nitride and silicon dioxide allows silicon nitride/dioxide planar waveguides to have a small mode size and low radiation bending loss compared with doped silicon dioxide waveguides. Small waveguide bend with low radiation loss can help make small integrated planar lightwave circuits (PLCs), and also high-Q waveguide ring resonators. This presentation will talk about the design, fabrication and characterization of low loss silicon nitride/dioxide planar waveguide devices including waveguide bend, waveguide cross, and leaky mode waveguide polarizer. The key contribution of this work is the use of the lateral mode interference (LMI) 3dB splitter to accurately measure the loss of the planar lightwave circuit devices. We will also talk about the waveguide ring resonators with silicon nitride/dioxide materials. The application for photonic biochemical sensors will also be discussed.

The latest results on the preparation and characterization of Er³⁺-doped fluoride glass channel waveguides are presented. The waveguides are prepared by means of ion exchange between fluoride and chloride ions, through a silica mask, on ZBLA (ZrF₄-BaF₂-LaF₃-AlF₃) fluoride glass substrate. Single mode propagation is demonstrated at 1.55 μm for a 10-mm long, 5-μm wide waveguide. Propagation losses are found to be not greater than 0.28 dB/cm. An "on/off' gain of 3.9 dB is measured at the output of a 1% Er³⁺-4% Ce³⁺-doped fluoride waveguide, with about 240 mW incident pump power at 980 nm. Modelisation studies show that net gain could be achieved in (Er³⁺, Ce³⁺) doubly-doped and (Er³⁺, Ce³⁺, Yb³⁺) triply doped fluoride waveguides.

Waveguides were written in Er-doped silica glasses by femtoscecond laser pulses. The waveguides exhibit a single mode at 632.8 nm with Gaussian profile and low propagation losses (<1dB over 4.8 mm). The optical properties like insertion losses and induced refractive index changes were measured and discussed. The optical gains at 1540 nm were measured as an active element in a standard waveguide amplifier setup. A maximum of 1dB internal gain at 200 mW, 976 nm pump were obtained.

Microstructured optical fibers are of increasing interest since they offer unique optical properties and design flexibility that cannot be achieved in conventional forms of fiber. We review structural features, fabrication, optical properties and potential applications of index-guiding holey optical fibers. The state-of-the-art is presented for both silica and compound glass holey fibers.

Bismuth oxide based highly nonlinear fiber (Bi-NLF) enabled by glass composition and small core fiber design was successfully fabricated. There's much expectation for the development of high nonlinearity optical devices along with the large volumetric and speed increase of the information traffic in recent years. In order to achieve higher nonlinearity, it is necessary to enlarge the nonlinear refractive index n₂ and make the effective core area Aeff smaller, as g is γ=2πn₂/(λA_eff). Much effort has been put into the development of small-Aeff holey fiber, as its high nonlinearity and dispersion can be controlled to a certain extent. However, holey fiber has issues such as large propagation loss, high connection loss with silica single-mode-fiber (SMF) because of their particular structure, and higher fabrication cost. We performed the fabrication of a conventional step-index-type SMF with high nonlinearity and low propagation loss using Bi₂O₃-based glass. First, we fabricated Bi₂O₃-based glass with high refractive index of >2.2 at 1550 nm by a conventional melting method. This glass exhibited extreme thermal stability for fiber drawing. Then in order to make A_eff smaller, cladding glass composition was designed so that the difference with the refractive index of the core glass must be large. Finally the core diameter was controlled to satisfy the single mode condition, and fiber drawing was performed. Typical A_eff of this fiber is less than 5 um². The nonlinearity g of the fiber can be estimated to be >600 W^-1km^-1, as large as the value reported in holey fibers using non-silica glass. Bi-NLF with step-index-type structure would become the best candidate for short length and highly nonlinear optical devices.

In this paper, we propose an innovative extremely harsh environment (up to 2000°C) distributed temperature sensor by fabricating in-fiber gratings in single crystal sapphire fibers. Temperature is sensed by changing grating optical spectral response. By cascading a set of gratings in the same single crystal sapphire fiber, distributed sensing can be achieved. A quantitative analysis on grating design, fabrication, and performance is presented. Some preliminary experimental results are also reported. Application of this unique in-fiber grating to extremely harsh environment temperature sensor will be performed in the near future.

We propose and demonstrate a powerful new approach to spectral bandpass engineering (apodization) of one-dimensional channel-waveguide Bragg reflectors. Bandpass engineering is accomplished via precise photolithographic control over the transverse width and longitudinal placement of individual grating lines which, respectively, provide unique line-by-line diffractive amplitude and phase control. Several channel waveguide gratings exhibiting complex filtering functions based on the present apodization method have been fabricated and modeled. They include an essentially polarization -insensitive 4-nm wide flat-top filter with steep roll-off and a multi-passband spectral decoder, useful, e.g., for optical spectral code-division multiplexing or spectral signature recognition. When a second-order apodization effect, comprising effective waveguide refractive index variation with grating-line transverse width, is included in the simulation, extraordinary agreement between predicted and observed spectral passband profiles is obtained.

Tunable filters are indispensable elements for tunable laser diodes, which provide an electronic control of the emission wavelength by exploiting the free-carrier plasma effect. A tunable filter consists of a combination of tuning region that forms a waveguide core and a Bragg grating for the wavelength-selective feedback. By injection of carriers into the tuning region, the refractive index and, thus, the Bragg wavelength can be decreased. Thereby, it is obvious that the maximum tuning range depends on the achievable carrier density in the tuning region. In this paper, a type-II diode is presented, which shows an improved carrier density-current characteristic. This is achieved by spatial separation of electrons and holes, which in turn leads to a suppression of carrier recombination. Since high carrier densities can be achieved at comparatively low injection currents, type-II superlattices are particularly well suited for application as tuning region in tunable filters. They have the potential to double the tuning range that is presently achievable using bulk tuning layers.

We propose an all-optical free-space interconnection with a photorefractive grating array for wavelength division multiplexing (WDM) signal. Input WDM signal propagating on free-space can be branched for each wavelength component and the components are connected to different spatial ports by this interconnection. The wavelength component of WDM signal is diffracted by one index grating, which is induced by two control beams, only when the phase-matching condition is satisfied. The phase-matching condition is determined by incident angles of control beams and the wavelength of the signal beam. By setting incident angles of control beams appropriately, it can be determined whether a wavelength component of WDM signal is diffracted by the index grating or not. The component can be connected to the desirable spatial output port by arraying the gratings with different grating vector. We analyze the diffraction efficiency to investigate the wavelength selectivity of this interconnection and investigate the influence of the multiplicity of the signal beam on the diffraction efficiency. As the results, the wavelength selectivity 0.7[nm], which is equivalent to that of the conventional arrayed-waveguide grating, is achieved when the waveband is 500-520[nm]. Moreover the diffraction efficiency 0.055 is obtained when the degree of multiplexing is 50.

We report hybrid electro-optic (EO) polymer/sol-gel waveguide modulators with a structure for an EO polymer confined laterally in a sol-gel over cladding, which is fabricated by all-wet etching process. The structure enables an adiabatic transition between the sol-gel waveguide and thick EO polymer overlayer. Intensity mode is confined well in 0.9-micron-thick EO polymer overlayer, which reduces a half wave voltage (V_π) due to increased overlap integral in the hybrid EO modulator. Straight channel birefringence EO modulators with the structure reduce the V_π by the factor of 4 after guided wave well confined in the EO polymer. The straight channel waveguide modulator with 2.4-cm-long electrode demonstrated the V_π of 13 V. Preliminary testing results using a Mach-Zehnder waveguide modulator were investigated to reduce the V_π further.

Inhomogeneous and anisotropic materials offer a rich variety of possibilities for constructing novel and efficient electro-optic and acousto-optic devices. Here we illustrate this by discussing some aspects of the acousto-optics of TeO₂, a material having a high degree of acoustic anisotropy, giving a design example. We also present some recent results concerning the electro-optics and acousto-optics of inhomogeneous structures, in the form of periodically poled LiNbO₃.

A cylinder-assisted Maker-fringe technique to probe second-order optical nonlinearity profiles is introduced. This technique presents several significant advantages over existing methods, including the measurement of fringes up to a record incidence angle of 89.6°, which is particularly useful for the accurate determination of the nonlinearity profiles of thin layers.

The second-order nonlinearity in poled optical fiber is promising for application to electro-optic switching and modulation, second-harmonic generation (SHG), and frequency conversion. In this paper, we poled a twin-hole fiber, which is similar to PANDA fiber but the strain applying part is vacant. Electrode wires were inserted into the side holes, and the fiber was poled with a voltage of 2.5 kV at 300°C for 40 min. We measured the SHG using a linearly polarized Q-switched Nd³⁺:YAG laser. The SH power was highest for polarization parallel with the direction of two holes. The SH power had a maximum for the fiber length of 5 cm and decreased for longer fiber lengths. We analyzed this phase matching considering cladding modes. We calculated numerically the propagation constants of the cladding modes. We showed that the ~40th-order cladding mode of the SH wave and the fundamental core mode of the fundamental wave are in phase matching. We also performed an SHG of poled twin-hole fiber using a 260-fs passively mode-locked Er³⁺-doped fiber laser as a fundamental-wave source. The SH signal from the poled fiber was proportional to the 1.82-th power of the fundamental power, and the polarization dependence agreed with that measured with an Nd³⁺:YAG laser. We discussed an application of the poled twin-hole fiber.

New infrared transmitting glass ceramics based on the Ge-Sb-S-CsCl system have been studied. By selecting an appropriate glass composition, glass ceramics with different quantities of micro-crystals can be reproducibly obtained with different annealing temperatures and durations. The presence of crystals induces some additional losses in the short wavelength region, namely between 0.6 and 2 μm. However, the glass ceramics keep the same transmission as the original glass after 3 μm up to 11 μm. To our best knowledge, it is the first time that highly reproducible glass-ceramics based on chalcogenide glasses are obtained. Compared to the glass, the corresponding glass-ceramics show better resistance to fracture propagation. The feasibility of shaping the glass-ceramics by molding has also been demonstrated.

In this work we report on visible upconversion emission in Er³⁺- and Ho³⁺-doped PbGeO₃-PbF₂-CdF₂-based transparent glass ceramics under 980 nm infrared excitation. In erbium-doped vitroceramic samples, blue(410 nm), green(530, and 550 nm) and red(660 nm) emission signals were generated, which were identified as due to the ²H_9/2, ²H_11/2, ⁴S_3/2, and ⁴F_9/2 transitions to the ⁴I_15/2 ground-state, respectively. Intense red(650 nm) upconversion emission corresponding to the ⁵F₅-⁵I₈ transition and very small blue(490 nm) and green(540 nm) signals assigned to the ⁵F_2,3-⁵I₈ and ⁴S₂,⁵F₄-⁵I₈ transitions, respectively, were observed in the holmium-doped samples. The 540 nm is the dominant upconversion signal in Ho³⁺-doped vitroceramics under 850 nm excitation. The dependence of the upconversion processes upon pump power and doping concentration are also investigated, and the main routes for the upconversion excitation processes are also identified. The comparison of the upconversion process in transparent glass ceramics and the precursor glass was also examined and the results revealed that the former present higher upconversion efficiencies.

Silicate glasses are among the best hosts for rare-earth ions, especially for the development of integrated optic amplifiers and lasers, due to their chemical robustness and adaptability to different waveguide fabrication processes. We performed a detailed study of a set of six experimental soda-lime silicate glasses, all having approximately the same base composition but doped with different percentages of Er³⁺ and Yb³⁺ ions. Judd-Ofelt analysis was performed on these glasses and the calculated radiative lifetimes were compared with the experimental ones. Planar waveguides were fabricated by using ion-exchange technology, and a new analytical function was used to fit the index profile of the waveguides. Luminescence and Raman spectroscopy was performed on most waveguide samples, and upconversion emission was evaluated. Channel waveguide insertion losses were reduced by using annealing processes, and net gain around 1535 nm was obtained. The gain, so far, is limited, but we are confident to be able to further increase the amplifier performances. Meanwhile, we are also developing a new type of silicate glass doped with alumina in order to increase the gain bandwidth.

Two series of ternary glasses with compositions of 0.5BaO-xB₂O₃-(0.5-x)P₂O₅ (Series 1) and (1-x)Ba(PO₃)₂-xB₂O₃ (Series 2) have been prepared. Various properties, such as refractive index (n), glass transition temperature (T_g), thermal expansion coefficient (a) and thermo-optic coefficient (dn/dT) have been measured to assess the potential of these borophosphate glasses for athermalisation. The results obtained for these glasses can be explained based on the incorporation of BO₃ and BO₄ units into the glass structural network. To achieve athermalisation, a negative dn/dT is required to counter the effect of thermal expansion.

The growth of lithium niobate doped with iron and doubly doped with Iron and Manganese ions with optimum growth parameters by using automatic diameter control Czochralski system designed is briefly described. The results of investigation of optical and some physical properties of these crystals are presented and compared with pure LN crystals.

Various material and functional properties have been measured in lithium niobate crystals (LiNbO₃) with different compositions, starting from conventional congruent composition, up to off-congruent and quasi-stoichiometric ones. The UV absorption edge has been measured and correlated with the crystal composition, showing the edge shift towards shorter wavelengths. The ferroelectric transition Curie temperatures have been determined by differential scanning calorimetry, and it increases with Li₂O content in the crystal. The surface composition has been checked by micro-Raman spectroscopy. A narrowing of the linewidths has been observed for quasi-stoichiometric crystal, showing an ordered structure, if compared with congruent composition. The coercive field has been measured as a function of temperature for two different crystal compositions, and it has been found lower in the off-congruent substrate. The Ti-indiffusion process has been studied and compared in congruent and off-congruent LiNbO₃ substrates by secondary ion mass spectrometry. The main diffusion process parameters have been determined. The Ti diffusion process has been found considerably slower in off-congruent substrates, if compared with conventional congruent LiNbO₃, and resulted almost isotropic. The Li-outdiffusion phenomenon has been observed and correlated wit the Ti concentration profile. A careful control on LiNbO₃ composition and material properties allows one to find the proper compositional window for the realization of various advanced optical and electro-optical devices.

Although fiber amplifiers have been employed in communications systems for many years, until very recently the fiber laser was little more than a scientific curiosity. However the fiber laser format has a number of intrinsic advantages over lamp and diode pumped YAG lasers including size, reliability, wavelength selectivity, heat dissipation, wallplug efficiency and operational cost; and with kiloWatt output powers now possible fiber lasers are beginning to replace lamp and diode pumped YAG lasers in many industrial applications. In this paper we review the recent and ongoing advances in fiber design that have facilitated this revolution.

The oscillation wavelength of a Nd³⁺-doped tellurite glass microsphere laser is controlled using a λΑ/4-shifted grating fabricated on the surface of the microsphere. The lasing wavelength is in agreement with the high transmission wavelength of the grating estimated from the grating period and the effective index of the whispering gallery mode.

We report on the temperature dependence of L-band laser emission of fiber-taper-coupled Er³⁺-doped tellurite glass microsphere. Pumping at 1480 nm instead of 975nm was used to enhance the coupling efficiency, reduce the internal thermal effect, and increase the output laser emission. The microsphere laser emission threshold increased and the emitted laser wavelength shifted with temperature. The experimental results are explained with a quasi-four-level model, showing that a significant reduction of laser threshold can be achieved at lower temperatures and higher Q values of this microsphere laser.

We observed optical properties from several kinds of Eu-chelates doped DNA-CTMA and PMMA films. The lifetime in DNA-CTMA was longer than in PMMA, and the quantum yield in DNA-CTMA was also higher than in PMMA. Among them, we calculated each cross section because we compared laser properties of Eu-chelates by interacting DNA-CTMA with PMMA. We will discuss the lasing capability by interacting DNA-CTMA.

Blue, green, red, and near-infrared upconversion luminescence in the wavelength region of 480 - 740 nm in Pr³⁺/Yb -codoped lead-cadmium-germanate glas under 980 nm diode laser excitation, is presented. Upconversion emission paks around 485, 530, 610, 645, and 725 nm which were ascribed to the ³P₀ - ³H_J (J=4, 5, and 6), and ³P - ³F_J (J=2, and 3,4), transitions, respectively, were observed. The population of the praseodymium upper ³P₀ emitting level was accomplished through a combination of ground-state absorption of Yb³⁺ ions at the ²F_7/2, energy-transfer Yb³⁺(²F_5/2) - Pr³⁺(³H₄), and excited-state absorption of Pr³⁺ ions provoking the ¹G₄ - ³P₀ transition. The dependence of the upconversion luminescence upon the Yb³⁺-concentration and diode laser power, is also examined, in order to subsidize the proposed upconversion excitation mechanism.

Rare earth-doped oxyfluoride glass of the 50SiO₂ -50PbF₂ -5ErF₃ composition in molar ratio was developed. When the oxyfluoride glass is heat-treated at the first cystallization temperature, the glass gives the glass-ceramic in which rare earth-containing fluorite-type nanocrystals of about 20 nm in diameter uniformly precipitate in the glass matrices. The glass-ceramic is trasnparent to the naked eye like no heat-treated oxyfluoride glass. The glass-ceramic exhibits highly efficient upconversion luminescence under 800 and/or 980 nm laser light excitation. On the other hand, the oxyfluoride glass can be locally changed to glass-ceramic in the forms of dot, line, plane, letter, etc. by thermal energies generated from light absorption of various lasers. In the case of CO₂ laser irradiation the formation of such glass-ceramic occurs near the surface of glass. In the case of 800 or 980 nm irradiation by Ti:sapphire laser or laser diodes, on the other hand, the formation of such glass-ceramic occurs near the surface and/or inside of glass. The glass-ceramic parts can be easily read by upconversion luminescence under laser excitation. Therefore, the presently developed rare earth-doped oxyfluoride glass can be utilized as optical devices of the writing and reading memory, which can be utilized as specific devices for security information.

It is well known that the efficiency of silica based Er/Yb fiber lasers and amplifiers can be greatly enhanced by a high level of phosphorus co-doping. The interaction of phosphorus with the rare earths and with the further co-dopant aluminium during the preparation process leads to peculiar effects concerning chemistry of dopant incorporation, diffusion behaviour and microscopic glass structure. Until now however, it has been disregarded that these interactions give rise to strong radial and even axial concentration profiles in preform and fiber (for the codopants phosphorus and aluminium, but also for the rare earth components erbium and ytterbium) with remarkable consequences for the laser efficiency. Here, we have studied the incorporation mechanism and the diffusion behaviour (diffusion coefficients in dependence on temperature and concentrations) by X-ray microprobe analysis concerning the dopant interaction effects. Moreover, we have investigated both fluorescence intensities and lifetimes, radially and axially resolved in the fiber preforms. The results were correlated with the properties of double clad fiber lasers made from these preforms. First attempts have been undertaken to interpret and control the incorporation mechanism on the basis of model calculations regarding phosphorus diffusion and chemistry.

We propose an all-optical interconnection with cross-polarized double phase conjugate mirrors (CP-DPCMs). In the interconnection, spatially arrayed signal beams from an input port two-dimensionally intersect with control beams from an output port in the photorefractive crystal (PRC) where polarizations of these two beams are orthogonal each other. The CP-DPCM can function as the switching element by adjusting the intensity ratio of these two beams because it strongly depends on the intensity ratio of crossing two beams whether the CP-DPCM is built up in the PRC or not. Thus the signal beam is diffracted by the CP-DPCM and propagated to the output port, when the intensity ratio of signal beam and control beam is adjusted to proper value for buildup of the CP-DPCM. This technique offers the point-to-point interconnection in two-dimensional plane. It implies the possibility of miniaturization and the integration by stacking the planes with different wiring pattern in layers compared to the conventional interconnections with DPCMs. For configuring the arbitrary wiring pattern, it is important to determine the intensities of the signal beams and the control beams, so we investigate the optimum intensities of these beams for effective switching. We carry out basic experiment on 1x2 interconnection with BaTiO₃ and Ar⁺ laser.

In this work, we report the optical properties of Tm³⁺ doped lead-niobium-germanate glasses (GeO₂-PbO-Nb₂O₅) for different Tm³⁺ concentrations ranging between 0.5 and 3 wt%. Judd-Ofelt intensity parameters have been determined to calculate the radiative transition probabilities and radiative lifetimes of excited states. Luminescence spectra and lifetimes were measured under 457 nm and 798 nm excitations. In this glass the infrared emission corresponding to the ³H₄→³F₄ transition is broader by nearly 40 nm if compared to fluoride glasses used for S- band amplifiers. The stimulated emission cross-section has been determined from the line shape of the emission spectra and the lifetime of level ³H₄.

In this work we report infrared to visible upconversion luminescence in the low phonon-energy host material KPb₂Cl₅ doped with Er³⁺ ions. The low phonon energy strongly reduces multiphonon relaxation in this host. As a consequence, in addition to the strong green upconversion luminescence from ²H_11/2,⁴S_3/2) levels at room temperature, blue luminescence from ²H_9/2 and ⁴F_7/2 levels is also observed under near infrared excitation in the ⁴I_9/2 (801 nm) and ⁴I_11/2 (978 nm) multiplets respectively. The upconversion mechanisms are investigated by means of excitation and timeresolved luminescence spectroscopy.

In this paper, the implementation of Gaussian apodized volume grating for a demultiplexer is presented. A 42-channel demultiplexer based on that grating is optically demonstrated. By using the Gaussian apodized grating, the crosstalk level between two channels is reduced down to -35dB. The bandwidth of a channel is 0.18 nm. The two adjacent fibers are seperated by 122.5-μm horizontal distance providing the wavelength spacing between each channel of 0.4 nm. Besides, for all 42 channels, the interchannel uniformity of 1.5 dB has been obtained.

When rare earth-doped oxyfluoride glasses are heat-treated at the first crystallization temperatures, the glasses turn into glass-ceramics in which rare earth-containing nanocrystals uniformly precipitate in the glass matrices. These glass-ceramics are transparent to the naked eye as well no heat-treated glasses. Since rare earth ions exist as solid-solution ions in the precipitated fluoride crystals with low phonon energies, these glass-ceramics exhibit highly efficient up-conversion luminescence by laser light excitation. In the present work, rare earth-doped oxyfluoride glass-ceramics in the SiO₂-PbF₂-HoF₃-YbF₃-GdF₃, and SiO₂-PbF₂-TmF₃-YbF₃-GdF₃ systems were developed. Under 980nm LD excitation the respective glass-ceramics gave selectively red-, green-, and blue-upconversion luminescence with high efficiency. Emission wavelengths in the center of gravity are 666, 543, and 479 nm, respectively. Except for these selective emissions, however, other emissions at different wavelengths are also observed, though extremely weak. Removal of these extra emissions was possible by using appropriate filter-glasses, presenting the up-conversion devices of individual emission of red (R), green (G), and blue (B). On the other hand, laminas of the mixtures of resin and the glass-ceramic powders exhibited extremely high enhancement of upconversion emission intensities. The developed upconversion glass-ceramics in which RGD emissions are independently available by 980 nm laser irradiation offer a variety of applications. Some of the expected utilization as optics devices is proposed.

Properties of defects induced by irradiation with a near-infrared femtosecond laser into a series of synthetic fused silicas containing different OH contents are reported. Comparing with the samples before laser irradiation, two absorption bands centered around at 4.8 and 5.8 eV which correspond to E'(≡Si•) center and non-bridging oxygen hole center (NBOHC, ≡Si--O•), respectively, were evidently observed after laser irradiation in high-OH silicas. A photluminescence band with photon energy of 1.9 eV was observed in the as-irradiated silicas under 4.8 eV light excitation. Though no red photoluminescence was observed after irradiated inside low OH-containing silica samples, a similar phenomenon occurs when the laser beam was focused near the surface of low-OH silicas. The induced structures were relaxed after annealing at 400°C. A possible model for the generation of 1.9 eV photoluminescence induced by ultrashort pulse laser in wet silicas and dry silicas was proposed.

Various measurements on Variable Optical Attenuator (VOA) based on ion-exchange waveguides in glass are presented. A Mach-Zehnder interferometer (MZI) was fabricated, and a thermo-optical effect was reached via heating electrodes besides the waveguides. The insertion loss (IL) of the device was 1dB, the dynamic range was 38dB and maximal power consumption was 138mW. Study concluded on the polarization origin allowed reduction of Polarization Dependent Loss (PDL) to 0.2dB/0.6dB at 10dB/20dB attenuations respectively