We investigate the impact of pulse interleaving and optical amplification on the spectral purity of microwave signals generated by photodetecting the pulsed output of an Er:fiber-based optical frequency comb. It is shown that the microwave phase noise floor can be extremely sensitive to delay length errors in the interleaver, and the contribution of the quantum noise from optical amplification to the phase noise can be reduced ∼10  dB for short pulse detection. We exploit optical amplification, in conjunction with high power handling modified unitraveling carrier photodetectors, to generate a phase noise floor on a 10 GHz carrier of -175  dBc/Hz, the lowest ever demonstrated in the photodetection of a mode-locked fiber laser. At all offset frequencies, the photodetected 10 GHz phase noise performance is comparable to or better than the lowest phase noise results yet demonstrated with stabilized Ti:sapphire frequency combs.

We demonstrate InP-based modified uni-traveling carrier photodiodes on silicon-on-insulator (SOI) waveguides with an internal responsivity of 0.85 A/W, up to 30 GHz bandwidth, and high RF output power. Photodiode arrays exceed a saturation current-bandwidth-product of 630 mA·GHz and +10 dBm RF output power at 20 GHz.

This talk will describe modified uni-traveling carrier photodiodes (MUTCs) that have achieved high RF output power and high saturation current. Discrete photodiodes, 4×1 phase matched arrays, and balanced detectors will be discussed.

InGaAs/InP-modified uni-traveling carrier photodiodes with cliff layer were designed and fabricated for V-band (50-75 GHz) applications. The devices were flip-chip bonded on AlN submounts for efficient heat dissipation. A high-impedance transmission line was designed to compensate for the parasitic capacitance and enhance the bandwidth. Devices with 3-dB bandwidths of 50 and 65 GHz demonstrated high-output RF power of 20.3 and 15.9 dBm, respectively.

Four-element modified uni-traveling-carrier (MUTC) photodiode arrays (PDA) flip-chip bonded onto transmission lines on AlN substrates are demonstrated. High RF output powers of 26.2 dBm and 21.0 dBm are achieved at 35 GHz and 48 GHz, respectively, using a PDA with 28-μm diameter photodiodes. A systematic comparison between a PDA with four 20 μm-diameter elements and a discrete detector with the same active area (40-μm diameter) is presented. The PDA achieved higher output power and thermal dissipation compared to its discrete counterpart.

We have developed a packaged photodetector module with an RF output power of almost 25 dBm at 10 GHz and more than 23 dBm at 15 GHz. To the best of our knowledge, these are the highest RF power levels ever reported from fully packaged 1.55 μm photodetectors without electrical amplification.

We describe noise limitations associated with Er:fiber-based optical frequency dividers. A low-noise Er:fiber laser combined with optimized photodetection results in 5 GHz signals having phase noise floors of -176 dBc/Hz.

We report InP/InGaAs modified unitraveling-carrier balanced photodiodes (PDs). The back-illuminated PDs were flip-chip bonded on diamond submounts for enhanced heat sinking. The device demonstrated a 3-dB bandwidth of 8 GHz and a 30-dB common-mode rejection ratio at frequencies of <; 10 GHz. High saturation current of > 320 mA, maximum output power of 31.7 dBm (1.5 W) into a 50-Ω load, and good linearity with a third-order intercept point of up to 47 dBm were measured at the 3-dB bandwidth frequency of 8 GHz.

High-speed photodetectors with large saturation photocurrent are key components in fiber optic links and photonic microwave applications. Recently, we demonstrated flip-chip bonded modified uni-traveling carrier photodiodes (MUTC PDs) that achieved high saturation current and high speed [1]. In the present work, MUTC PDs are fully packaged and characterized under high-power large-signal modulation conditions. The devices achieve 13 dBm RF output power at 30 GHz, an output third-order intercept point (IP3) up to 36 dBm, low amplitude-to-phase (AM-to-PM) conversion coefficient, and are suitable to detect 42 Gbit/s data streams with peak-to-peak voltage Vp-p as high as 2.4 V.

We present monolithic integrated uni-traveling-carrier balanced photodiode flip-chip bonded on diamond. The devices with bandwidth of 15 GHz and 20 GHz demonstrated maximum output power of 27.4 dBm and 24.1 dBm, respectively.

We report on packaged photodiode modules based on modified uni-traveling carrier photodiodes (MUTC-PDs). Modules with MUTC-PDs flip-chipped on Aluminum Nitride (AlN) and an active area diameter of 40 μm were developed. The module demonstrated a 3-dB bandwidth of up to 17 GHz. High saturated RF output power was achieved with 25 dBm output power at 10 GHz and 23.8 dBm at 15 GHz. Also, using a two tone experimental setup we measured the output 3rd order intercept point (OIP3) at 10 GHz to be over 30 dBm. Additionally, modules with MUTC-PDs flip-chipped on a Diamond substrate and an active area of 20 μm were developed. The modules exhibited a 3-dB bandwidth up to 30 GHz and an RF output power of 17 dBm at 30 GHz. To the best of our knowledge, these are the highest RF power and OIP3 levels ever reported in this frequency range from a packaged photodiode.

Narrowband high-power photodiodes (PDs) are promising candidates for analog photonic systems including RF antenna transmitter applications and low phase noise photonic oscillators. Our previous work has demonstrated that wideband modified uni-travelling-carrier (MUTC) PDs with cliff layer [1] can achieve high power at high frequency and that their performance can be further enhanced by flip-chip bonding on high thermal conductivity AlN substrates[2,3]. Here we present our recent work on developing narrowband MUTC-PDs to improve power efficiency (η ρ ) and AC Responsivity (R AC ).

We present monolithic integrated uni-traveling-carrier balanced photodiode flip-chip bonded on diamond. The devices with bandwidth of 15 GHz and 20 GHz demonstrated maximum output power of 27.4 dBm and 24.1 dBm, respectively.

For the first time we demonstrate evanescently-coupled modified uni-traveling carrier photodiodes (MUTC PDs) on silicon-on-insulator (SOI) waveguide with an internal responsivity of 0.85 A/W, up to 15 GHz bandwidth, and high RF output power. A novel 2-element MUTC PD array has a saturation current-bandwidth-product of >;630 mA*GHz and achieves +9 dBm RF output power at 20 GHz.

A high-linearity balanced photodetector with a record-high RF output power of 16 dBm at 40 GHz is presented. The third order intercept point at 15 GHz reaches 34 dBm. By operating one photodiode in the non-linear regime we observe partial cancelation of intermodulation distortions in common mode.

A stable optical frequency is phase-coherently divided to generate ultralow-noise 10 GHz signals having phase noise below -100 dBc/Hz at 1 Hz and a white noise of -177 dBc/Hz at higher offset frequencies. We discuss the technical and fundamental challenges of this approach, along with potential for integration of the components in a portable and robust system.

High-linearity modified uni-traveling carrier photodiodes on silicon-on-insulator with low AM-to-PM conversion factor are demonstrated. The devices deliver more than 2.5 dBm RF output power up to 40 GHz and have an output third order intercept point of 30 dBm at 20 GHz. Photodiode arrays exceed a saturation current-bandwidth-product of 630 mA · GHz and reach unsaturated RF output power levels of 10 dBm at 20 GHz.

This talk will describe modified uni-traveling carrier photodiodes (MUTCs) that have achieved high RF output power and high saturation current. Discrete photodiodes, 4×1 phase matched arrays, and balanced detectors will be discussed.

We propose and demonstrate a novel InP-based evanescently-coupled modified uni-traveling carrier photodiode (MUTC PD) on SOI waveguide. A 100-µm long waveguide MUTC PD reaches a third-order local intercept point (IP3) of 20 dBm at 7 GHz and 10 mA.

Modified uni-traveling carrier (MUTC) photodiodes with diameter of 28 μm and 20 μm flip-chip bonded on AlN substrate demonstrated RF output power of 25 dBm and 19 dBm at 25 GHz and 30 GHz, respectively.