Low-threshold diode-laser-pumped OPOs based on QPM materials
Although attractive as compact sources of tunable infrared radiation, optical parametric oscillators pumped directly by single-mode diode lasers require extremely low thresholds. This talk will discuss the realisation of such low-threshold devices using QPM materials.
Doubly resonant continuous-wave optical parametric oscillator pumped by a single-mode diode laser.
The performance characteristics of a doubly (signal and idler) resonant continuous-wave optical parametric oscillator based on periodically poled lithium niobate and pumped by a 100-mW single-mode laser diode at 810 nm are reported. Pump power thresholds as low as 16 mW and wavelength tuning over the range 1.15-1.25 microm at the signal and 2.31-2.66 microm at the idler were achieved through variation of crystal temperature, pump wavelength, and grating period. Up to 5 mW of signal output was obtained with the single-mode diode pump, and signal powers of up to 39 mW were obtained when pumping with a 400-mW injection-locked broad-area diode laser.
Nietzschean Genealogy and Hegelian History in The Genealogy of Morals
I would like to offer an interpretation of the Genealogy of Morals, of the relationship of master morality to slave morality, and of Nietzsche's philosophy of history that is different from the interpretation that is normally offered by Nietzsche scholars. Contrary to Nehamas, Deleuze, Danto, and many others, I wish to argue that Nietzsche does not simply embrace master morality and spurn slave morality. I also wish to reject the view, considered simply obvious by most scholars, that the Übermensch develops out of, or on the model of, the master, not the slave. And to make the case for all of this, I want to explore the relationship between Hegel's master-slave dialectic and the conflict Nietzsche sees between master morality and slave morality. That Nietzsche does not intend us to recall the famous master-slave dialectic of Hegel's Phenomenology as we read the Genealogy of Morals, I find difficult to believe. Yet very few commentators ever notice, let alone explore, this connection.