Doped Polymer Waveguide Research Articles

Demonstration of Optical Gain at 1535 nm Based on ErIII Complex‐Doped Polymer Waveguides Under Light‐Emitting Diode Excitation

AbstractA near‐infrared luminescent complex Er(DBTTA)3(DBFDPO) [where DBTTA = dibenzotetrathienoacene; DBFDPO = 4,6‐bis (diphenylphosphoryl) dibenzofuran] is synthesized. Based on the intramolecular energy transfer between organic ligands and Er3+ ions, optical gains at 1535 nm are demonstrated in Er(DBTTA)3(DBFDPO)‐doped polymer waveguides under the excitation of light‐emitting diodes (LEDs) instead of laser pumping. Relative gains of 6.4, 8.2, and 10.6 dB are obtained in 1 cm long waveguides with cross‐sectional dimensions of 6 × 4, 4 × 4, and 2 × 3 µm2 respectively, using the vertical top‐pumping mode of a 365 nm LED with 462 mW. Incorporating an ≈100 nm thick aluminum reflector grown under the lower cladding, enhanced the optical gain to 11.6 dB cm−1 in a waveguide with a cross‐section of 4 × 4 µm2, and an internal gain of ≈7.4 dB cm−1 is achieved. By relying on the intramolecular energy transfer and LED top‐pumping technology, the upconversion luminescence of Er3+ ions and thermal damage to polymer waveguides caused by the high power density of laser pumping can be effectively reduced. The complex Er(DBTTA)3(DBFDPO)‐doped polymer can be spin‐coated on different types of waveguides to compensate for optical losses at 1.5 µm and is expected to have a critical role in planar photonic integration.

High‐Gain of NdIII Complex Doped Optical Waveguide Amplifiers at 1.06 and 1.31 µm Wavelengths Based on Intramolecular Energy Transfer Mechanism (Adv. Mater. 12/2023)

Active Polymer Waveguides In article number 2209239, Hui Xu, Dan Zhang, and co-workers report high gains at 1.06 and 1.31 μm wavelengths in a novel complex Nd (TTA)3(XPO)-doped polymer waveguide with the excitation by light-emitting diodes (LEDs) instead of a semiconductor laser as the pump source. The importance of this work is to minimize the commercial cost of waveguide amplifiers in planar photonic integration.

High-Gain of NdIII Complex Doped Optical Waveguide Amplifiers at 1.06 and 1.31µm Wavelengths Based on Intramolecular Energy Transfer Mechanism.

Chelate phosphine oxide ligand (9,9-dimethyl-9H-xanthene-4,5-diyl) bis (diphenylphosphineoxide) (XPO) is prepared as a neutral ligand to synthesize complex Nd (TTA)3 (XPO) (TTA = 2-thenoyltrifluoroacetone). An appropriate energy gap between the XPO and TTA ligands, which can support two additional energy transfer routines from the first excited triplet state (T1 ) energy level of the XPO to that of the TTA, improves energy transfer in the Nd complex. Based on intramolecular energy transfer mechanism, optical gains at 1.06 and 1.31µm are demonstrated in Nd (TTA)3 (XPO)-doped polymer waveguides with the excitation of low-power light-emitting diodes (LEDs) instead of semiconductor lasers as pump sources. Using the vertical top-pumping mode of a 365nm LED, relative gains of 22.5 and 8.4dBcm-1 are obtained at 1.06 and 1.31µm, respectively, in a 0.2 cm long embedded waveguide with a cross-section of 8×5µm2 . The active core layer is Nd (TTA)3 (XPO)-doped SU-8 polymer. Moreover, relative gains are achieved in evanescent-field waveguide with a cross-section of 6×4µm2 . The 21.0 and 5.6dBcm-1 relative gains are achieved at 1.06 and 1.31µm, respectively, with a net gain of 13.8±0.3dBcm-1 obtained at 1.06µm in a 0.9 cm long SU-8 waveguide with Nd (TTA)3 (XPO)-doped polymethylmethacrylate as upper cladding.

Optical gain at 1.55 µm of Er(TMHD)3 complex doped polymer waveguides based on the intramolecular energy transfer effect.

Based on the intramolecular energy transfer mechanism between organic ligand TMHD (2, 2, 6, 6-tetramethyl-3, 5-heptanedione) and central Er3+ ions, optical gains at 1.55 µm were demonstrated in three structures of polymer waveguides using complex Er(TMHD)3-doped polymethylmethacrylate (PMMA) as the active material. With the excitation of two low-power UV light-emitting diodes (LEDs) instead of 980 or 1480 nm lasers, relative gains of 3.5 and 4.1 dB cm-1 were achieved in a 1-cm-long rectangular waveguide with an active core of Er(TMHD)3-doped PMMA polymer. Meanwhile, relative gain of 3.0 dB cm-1 was obtained in an evanescent-field waveguide with cross-section of 4 × 4 µm2 using passive SU-8 polymer as core and a ∼1-µm-thick Er(TMHD)3-doped PMMA as upper cladding. By growing a 100 nm thick aluminum mirror and active lower cladding, the optical gain was doubled to 6.7 dB cm-1 in evanescent-field waveguides because of the stimulated excitation of Er3+ ions in the upper and lower cladding and the improved absorption efficiency.

Identification of dyes and matrices for dye doped polymer waveguide emitters covering the visible spectrum

Polymer based photonic devices offer the possibility cost effective roll-to-roll manufacture of photonic devices. The incorporation of luminescent dopants within a solid polymer waveguide allows for the generation of light within the device avoiding tedious mechanical light coupling. However, when a dopant is embedded in a solid matrix, depending on its concentration and the nature of materials involved, the emitted light may be quenched due to aggregation effects. In this work, thin films and ridge waveguides processed by UV-photolithography have been successfully obtained from a selection of standard photopolymerizable organic monomers, SU8, EpoCore and OrmoStamp doped with a selection of standard dyes like Rhodamine-B, Coumarin-540A and Pyrromethene-580. All structures were manufactured on glass substrates. An analysis of the solubility and optical properties including band gap energy, absorption coefficient (alpha ) and fluorescence of the doped photoresists at different concentrations has been performed. Photoresists doped with Rhodamine-B shows a higher energy of indirect allowed band gap transition (2.04–2.09 eV) compared to previously reported pure Rhodamine-B thin films (1.95–1.98 eV). Fabrication protocols of dye doped photoresists covering the entire visible spectrum is established.

Design and Application of Waveguide Microwave Electron Synthesis Power Amplifier Using Er3+−Yb3+ Co-Doped Nanocrystalline

The solid-state power device has the advantages of small size, light weight and low working voltage, but the output power of the device is limited and cannot meet the engineering needs of power synthesis. Based on the characteristics of erbium (Er3+)-doped optical waveguide amplifier (EDWA), Er3+-ytterbium (YB3+) nanocrystalline were introduced into the design of solid-state power devices, and then nanoelectronic devices were designed to improve the output power of the device. First, NaYF4: 8%Er3+, 16%Yb3+ nanocrystalline were prepared. SU-8 UV glue was used to prepare NaYF4: Er3+. Yb3+ nanocrystalline doped polymer waveguide amplifier was designed and used to observe the waveguide morphology and its performance was tested. Then, the power synthesis amplification technology was studied, and the power distribution-synthesis network based on waveguide E–T junction was designed. The waveguide-microstrip transition structure adopted ridge waveguide transition. On this basis, the 4-stage waveguide E-plane stepped structure was introduced and its structure was simulated. In the design of the power synthesis amplifier, the signal gain of the synthesis amplifier was tested by using the nanocrystal-doped polymer waveguide amplifier as the power unit device. The experimental results show that the output signal light of the nanocrystal-doped polymer waveguide amplifier can be received by an infrared detector. When the pump light power at 980 nm is 200 mW and the signal light power is only 0.1 mW, the maximum relative gain is 4.7 dB in a 1.2 cm long waveguide. The saturated output power of the power unit device is 19.3 dB~19.8 dB, which is close to the saturated output power required by the chip manual. The gain curve of the power synthesis amplifier is relatively flat, that is, the use of nanocrystal-doped polymer waveguide electronic devices effectively improves the synthetic signal gain and reduces the adverse impact of power distribution-synthetic passive network loss.

KMnF3:Yb3+,Er3+@KMnF3:Yb3+ active-core–active-shell nanoparticles with enhanced red up-conversion fluorescence for polymer-based waveguide amplifiers operating at 650 nm

We demonstrated optical amplification at 650 nm in KMnF3:Yb3+,Er3+@KMnF3:Yb3+ nanoparticles doped polymer waveguides for the first time.

Optical Amplification at 1525 nm in BaYF5: 20% Yb3+, 2% Er3+ Nanocrystals Doped SU‐8 Polymer Waveguide

We demonstrated optical amplification in BaYF5: 20% Yb3+, 2% Er3+ (BYF) nanocrystals doped polymer waveguide. BYF nanocrystals with an average size of ∼13 nm were synthesized by a high‐boiling solvent process. Intense 1.53 μm fluorescence was obtained in the nanocrystals under excitation at 980 nm. An optical polymer waveguide was fabricated by using BYF nanocrystals doped SU‐8 polymer as the core material. A relative optical gain of ∼10.4 dB at 1525 nm was achieved in a 1.1 cm long waveguide for an input signal power of ∼0.09 mW and a pump power of ∼212 mW.

Amplified spontaneous emission and optical gain measurements from pyrromethene 567 �?? doped polymer waveguides and quasi-waveguides: erratum

Amplified spontaneous emission and optical gain measurements from pyrromethene 567 �?? doped polymer waveguides and quasi-waveguides: erratum

Amplified spontaneous emission and optical gain measurements from pyrromethene 567 �?? doped polymer waveguides and quasi-waveguides

Amplified spontaneous emission from planar waveguides and quasi-waveguides based on Pyrromethene 567-doped poly(methyl methacrylate) thin films deposited onto quartz and glass substrates is investigated. Films with different thickness were prepared and pumped optically at 532 nm with pulses of up to 8 MW/cm(2). Pump thresholds for the onset of ASE emission, optical gains and losses were assessed. Net gain coefficients were estimated by fitting the data provided by variable stripe length measurements with a theoretical expression which takes into account saturation. In this way, net gain coefficients of up to 56 +/- 9 cm(-1) at a pump intensity of 5.3 MW/cm(2) for quasi-waveguides and up to 20.6 +/- 2.7 cm(-1) at a pump intensity of 3.4 MW/cm2 for waveguides, were obtained. Loss coefficients in the waveguides were estimated to be 3.8 +/- 0.4 cm-1 and 6.1 +/- 1.3 cm(-1) for 15 microm and 5 microm thick films, respectively. The results obtained seem to indicate a stronger self-mode-restriction capability in the quasiwaveguides than in conventional total internal-reflection waveguides.

All-optical switch and modulator using photochromic dye doped polymer waveguides

Abstract We have fabricated all-optical 1×2 Y-branch switch and Mach–Zehnder modulator using photochromic dye doped polymer waveguides. The photochromic dye undergoes reversible structural change from the open form (low refractive index) to the closed form (high refractive index) by irradiation with ultraviolet (365 nm) light and in the reverse direction by irradiation with visible (514 nm) light. The 1×2 Y-branch switch exhibited a cross talk of about −14 dB and the Mach–Zehnder modulator exhibited an extinction ratio of about −12 dB at the wavelength of 1.55 μm using the ultraviolet (365 nm) and visible (514 nm) lights. A simple kinetic model has been used to calculate the refractive index change by the induced photochromic effect. The evolution of the refractive index change is successfully applied to predict the evolution of modulation characteristics.

Rare-earth doped polymers for planar optical amplifiers

Optical waveguide amplifiers based on polymer materials offer a low-cost alternative for inorganic waveguide amplifiers. Due to the fact that their refractive index is similar to that of standard optical fibers, they can be easily coupled to existing fibers with low coupling losses. Doping the polymer with rare-earth ions that yield optical gain is not straightforward, as the rare-earth salts are poorly soluble in the polymer matrix. This review article focuses on two different approaches to dope a polymer waveguide with rare-earth ions. The first approach is based on organic cage-like complexes that encapsulate the rare-earth ion and are designed to provide coordination sites to bind the rare-earth ion and to shield it from the surrounding matrix. These complexes also offer the possibility of attaching a highly absorbing antenna group, which increases the pump efficiency significantly. The second approach to fabricate rare-earth doped polymer waveguides is obtained by combining the excellent properties of SiO2 as a host for rare-earth ions with the easy processing of polymers. This is done by doping polymers with Er-doped silica colloidal spheres.

All-optical bistability in doped-polymer film waveguides

All-optical bistability was observed in thin-film waveguides made with acceptor-donor substituted azobenzene-doped poly(methyl methacrylate) polymer. Input-output curves with hysteresis characteristics were measured. The origin of the bistability was attributed to nonlinear coupling between a prism and a doped-polymer waveguide. An approximately theoretical analysis was introduced. Theoretical predictions were qualitatively consistent with experimental results.

Two-photon pumped upconverted lasing in dye doped polymer waveguides

The first measurements of two-photon pumped upconverted lasing in a waveguide is reported. Nonlinear dependence of the upconversion signal on the square of the input pump intensity and associated spectral narrowing was experimentally observed in dye-doped polymer waveguides. The pump wavelength was 736 nm and the center of the lasing spectrum was 570 nm. The spectra shows excitonlike features at 630 and 654 nm not seen in the absorption spectrum.